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January 2021 Zeta Alliance Weekly Call Summaries

Posted: Tue Jan 05, 2021 9:55 pm
by rleiker
Hello Zimbra Community,

Here is a summary of this week’s conference call. A few brief reminders:

January 5, 2021

Safari 14.0.2 Issues With Zimbra
Mark S. said that after updating to Safari 14.0.2, as part of the MacOS upgrade to Big Sur, he has noticed that, for mailboxes with two-factor authentication enabled, Safari sometimes fails to proceed past the Zimbra Web Client login page to the two-factor authentication page. In other cases, Safari crashes about once per week, and he has found that he cannot scroll in certain places in the Zimbra Admin Console, or there are screen painting issues. Cine commented that he has a friend, who is an Apple developer, and they have indicated that the most recent release of Safari has some known memory management issues. Apple is reportedly trying to decide if they should release a one-off patch to address these issues, or if they should wait for the next patch roll-up to be released. Noah P. said that he too has experienced some of these same issues with Safari, in that it has crashed about every other day for him since installing the Bur Sur update.

Microsoft’s One Outlook/Monarch Initiative
Randy L. shared an article ( ... e-outlook/ ) discussing Microsoft’s plans to discontinue the standalone Mail and Calendar apps in both Windows 8.x and Windows 10, and later the Windows and Mac desktop versions of Outlook, in favor of a single version of Outlook, which they are referring to as “One Outlook” or “Monarch”. He wondered if the earlier discussed Microsoft plans to replace EWS support in Outlook for the Mac with Microsoft Sync (refer to the August 11, 2020 Zeta Alliance call summary: viewtopic.php?f=9&t=68589#p298678
) is just another part of the One Outlook initiative. Since Zimbra supports both ActiveSync and EWS for syncing email, contacts, calendars, and tasks, this could have an impact on future sync options for Zimbra users.

Upcoming Zimbra Patches And New Zimbra Connector Release
Mark S. commented that the Zimbra Partner Portal indicates that 8.8.15 Patch 18 and 9.0 Patch 11 are scheduled to come out in late January. John H. said that either the January P18 and P11 releases or the February P19 and P12 releases are anticipated to include a new version of the Zimbra Connector for Outlook (ZCO) where an additional feature will be available to minimize the size of an Outlook PST file. Outlook officially supports PST files up to 50 GB in size, but with Windows registry tweaks, it is possible to force Outlook to accept larger PST sizes, however those larger sizes are not officially supported by Microsoft. John explained that the upcoming new version of ZCO builds on a feature that was introduced back in 9.0 Patch 7 ( ) and 8.8.15 Patch 14 ( ) that allowed for setting Windows registry keys to limit the amount of mailbox data that Outlook synchronizes from a Zimbra server in to a PST file. The P7 and P14 releases required rebuilding a new Outlook PST file for the change to take effect. The new upcoming ZCO feature will instead enable a more user-friendly setting by allowing an arbitrary date to be set from the Zimbra tab within Outlook, so that any synchronized data in the PST file stored prior to this date is removed from the current PST file, without needing to first build a new PST file to put the change in to effect. If a mailbox user needs to access older data, such as email messages prior to the cut-off date set in the Zimbra Outlook tab, then the user will need to login to the Zimbra Web Client to access that data.

New Zextras 3.1.6 Release
Mark S. said that he noticed Zextras released version 3.1.6 ( ... /home.html) and asked for clarification on the fix identified as issue ID BCK-403 related to S3 bucket commands from the Zimbra command line interface (CLI). Cine said there were a few commands for S3 buckets that have been moved from the Zextras Powerstore component to the Zextras Core, since those same commands are applicable to additional features in Zextras, aside from Powerstore. Mark S. also asked if Zextras version 3.1.6 is anticipated to be included in the upcoming Zimbra 8.8.15 Patch 18 and 9.0 Patch 11 releases tentatively scheduled for late January. John H. said that this Zextras version does tentatively appear to be included in the upcoming Zimbra 8.8.15 P18 and 9.0 P11 releases.

Randy Leiker
Skyway Networks, LLC

Re: January 2021 Zeta Alliance Weekly Call Summaries

Posted: Wed Jan 13, 2021 4:29 am
by rleiker
Hello Zimbra Community,

Here is a summary of this week’s conference call. A few brief reminders:

January 12, 2021

CentOS Alternative Options For Running Zimbra
Following the recent surprise announcement by the CentOS project to switch their focus to CentOS Stream for future releases ( ... os-stream/ ), Noah P. shared that he is looking at using AlmaLinux ( ) as an upgrade path from the current CentOS project releases on which to run Zimbra. AlmaLinux describes itself as a 1:1 binary compatible fork of Red Hat Enterprise Linux (RHEL) 8, built by the creators of the CloudLinux distribution. Noah asked if anyone had insights to share as to what Zimbra’s support for binary compatible replacements to RHEL/CentOS might look like for future Zimbra releases. No one on the call had an answer for Noah’s question. Randy L. commented that he has also read about another distribution in the works called Rocky Linux ( ), that is being coordinated by one of the founders of the CentOS project, and is likewise intended to be a drop-in replacement for CentOS.

Ubuntu 20.04.1 LTS Support For Zimbra
Marc G. asked if Synacor has any updates on when a supported Zimbra version for Ubuntu 20.04.1 LTS might be released, as his company is currently deploying new servers for Zimbra and would prefer to deploy with a more recent release of Ubuntu, rather than Ubuntu 18.04 LTS, which is the latest version of Ubuntu currently supported by Zimbra. John E. said that it is anticipated that Zimbra will have official support for Ubuntu 20.04.1 LTS in the first half of 2021, and is being tracked by internal Zimbra ticket # ZCS-9496, however the status of this ticket cannot be checked from the Zimbra Support Portal. To fix this limitation, John H. created a new Zimbra request for enhancement ticket (ZRFE-595) on the call, which can now be checked from the Zimbra Support Portal, as updates on the status for Ubuntu 20.04.1 LTS support become available from Synacor.

Follow-Up: Safari 14.0.2 Issues With Zimbra
Cine asked if anyone had any updates to share on the issue reported by Mark S. In last week’s call ( viewtopic.php?f=9&t=69121#p300106 ) related to the Safari 14.0.2 issues. No one had updates to share. Marc G. said he is on MacOS 14.0.2 (Catalina) and has not seen any issues, which seems to indicate that the Safari issues are limited in scope to those running the Big Sur version of MacOS.

Upgrade Options For Zimbra 9’s Modern UI And Zimlet Compatibility
Barry D. asked if anyone had recently rolled out the Zimbra 9 Modern UI to their users lately. No one on the call had experiences to share. Marc. G. said that what is holding back an upgrade to Zimbra 9 and a roll out of the Modern UI to his customers is that he is concerned if a wide roll out will create a number of support issues as customers begin using the new UI, since development of the Modern UI has been very rapid as of late, and wondered when it will begin to settle, especially the UI’s Zimlet interface. John E. explained that Marc should consider proceeding with an upgrade to Zimbra 9, but retaining the Classic UI as the default, since both the Classic and Modern UIs can co-exist within Zimbra 9. He also said that Marc could then gradually migrate customers from the Classic to the Modern UI as their comfort and experience with it increased, avoiding a sudden change. Barry D. added that while there are some continuing changes in the Zimlet interface for the Modern UI in Zimbra 9, there have not been any big changes lately, with most changes being incremental in nature.

Mixed-Mode Upgrades From Zimbra 8.8.15 To 9.0
Marc G. asked if a mixed-mode upgrade, where some Zimbra servers in a cluster are running 8.8.15 while others are running 9.0 is still possible. John H. and John E. said that this has been done for customer upgrade engagements that Synacor has worked on, but is best avoided if possible, as it can lead to unexpected results. Cine said that Zextras internal testing of mixed-mode upgrade scenarios suggest that most things in Zimbra should work fine, but that only the Classic UI should be used, and the Modern UI avoided, until all Zimbra servers in a cluster are upgraded to 9.0.

Compatibility Of Zimlets Developed For Zimbra 8.8.x In Zimbra 9
Randy L. said that what is holding back his company’s upgrade to Zimbra 9 is that there are multiple Zimlets currently deployed that were designed for Zimbra 8.8.x and he is under the impression that these Zimlets will not operate in Zimbra 9. Barry D. and John E. explained that in fact, Zimlets developed for Zimbra 8.8.x are very likely to work just fine in Zimbra 9’s Classic UI, but they will not work in Zimbra 9’s Modern UI, since it uses a new framework for Zimlets.

Updating The Classic UI Theme And Transitioning To the Modern UI
Mrac. G. asked if the new Zextras theme for the Classic UI ( ) can be used with Zimbra 9. Cine said it is compatible with both Zimbra 8.8.x and 9, Open Source and Network Edition. Marc G. said that he is thinking about using the new Zextras theme as a means to refresh the Classic UI as an interim step to transitioning his Zimbra customers to the Modern UI at a later date. John E. asked if there were specific features in the Modern UI that Marc was waiting on to be implemented. Barry D. said that in terms of feature parity to the Classic UI, the Modern UI is currently very close. John E. confirmed that the list of features to port to the Modern UI has dwindled considerably. Noah P. asked if he upgrades to Zimbra 9, does the Modern UI today largely represent what the Modern UI is intended to be? John E. said that it should be mostly complete. He also said that there is a group of UI features that do not directly translate from the Classic to the Modern UI, since those features have become irrelevant, as the Modern UI has changed the approach in which UI features are implemented. He encouraged customers and partners to express their desired features for the Modern UI to Synacor to ensure they are implemented as soon as possible. Noah P. said that a known limitation exists in the Zimbra 8.8.15 Classic UI, that prevents the password recovery/reset feature in Zimbra from being used when two-factor authentication is enabled for a mailbox. He asked if this limitation will be resolved in the Zimbra 9 Modern UI. John E. said he was not aware of this, but would check in to it and report back later.

Calendar Invite Issue For Requests Sent From Microsoft Teams
Marc G. said that a colleague using Office 365 is sending him calendar invites via Microsoft Teams, but upon receipt, the invite appears in the Zimbra Web Client (ZWC) as an unknown attachment. When examined using an external text viewing app, he said that the invite appears at first glance to have the expected iCalendar formatting and content. He also said that if he downloads the email containing the calendar invite in to an IMAP client on his desktop computer, that the invite then appears correctly as the expected ics file. John E. asked if perhaps the sender was sending Marc G. a TNEF encoded file ( ... ion_Format ), and if so, the ZWC has a built-in utility that attempts to auto convert TNEF files in to a usable format for non-Microsoft email apps, however this conversion only occurs within the ZWC, and not for email downloaded by outside email client apps. Marc said he did not see any indications that the calendar invite was TNEF encoded, so John E. and John H. suggested that Marc should open a Zimbra support case and include a complete unaltered copy of the calendar invite for Zimbra to analyze the headers and MIME type of the file. Cine also asked if Marc experiences this issue for one-time appointments, or recurring appointments only. Marc G. said that it has been happening with recurring appointments, and to troubleshoot, he has had the calendar event organizer delete and re-create a new recurring event, but that has not helped resolve the issue.

Randy Leiker
Skyway Networks, LLC

Re: January 2021 Zeta Alliance Weekly Call Summaries

Posted: Fri Jan 22, 2021 8:01 pm
by rleiker
Hello Zimbra Community,

Here is a summary of this week’s conference call. A few brief reminders:

January 19, 2021

Setting A Maximum Message Size Per Domain
Noah P. said that he is looking for a means to enforce a maximum email size limit per Zimbra domain. He explained that he has two customers that want to keep email messages within their organizations smaller than they are now, and Noah does not wish to apply the lower size limit to all other customer domains on his Zimbra servers, but rather just to those two customer’s domains. Cine suggested that CBPolicyd ( ) might be of help, and said that he knows CBPolicyd can set a maximum outbound message size limit, but was not certain if it was possible to set an inbound message size limit too. Mark S. suggested that Noah could setup a new Zimbra MTA server specifically for the customers requesting the lower message size limit, then route all of the email for those two customers through the new MTA server. Matthew F. said that writing a Postfix Milter to filter based on message size might work, but the downside to this approach would be that messages that are too large would bounce to the sender only after Zimbra initially accepts the messages for delivery. Matthew also pointed out that in doing a quick Telnet connection test to his Zimbra MTA server, he noticed that Postfix advertises the maximum message size accepted immediately after the HELO/EHLO command is sent, suggesting that it may only be practical to have a server-wide message size limit set, as compared to a per domain setting, assuming that all of the users are using the same Zimbra MTA server.

Resetting Mailbox Passwords When Two-Factor Authentication Is Enabled
John E. shared an update on an issue discussed in an earlier Zeta Alliance call related to difficulties encountered when attempting to use the Zimbra password reset feature for a mailbox with two-factor authentication enabled. He said that this has been acknowledged by Zimbra as a bug (ZCS-10191; status updates are not available via the Zimbra Support Portal) and is anticipated to be fixed in an upcoming patch that should be released soon. Noah P. asked if the bug fix will only apply to the Modern UI, the Classic UI, or both in Zimbra 9. John E. said that the bug fix is associated with the server back-end, so he thinks it should apply to both the Modern and Classic UIs.

Using Shared Calendars Containing The Same Calendar Event UIDs
From the Zeta Alliance mailing list, Frederic N. said that he has Zimbra users who have multiple shared calendars, and they often add the same calendar events to these multiple shared calendars with the same UID number. His users report that when their email clients are configured to synchronize each of these shared calendars, they expect the calendar events with the same UID number to appear for each shared calendar, but the actual behavior observed is that the calendar events appear only once on a single shared calendar – usually the shared calendar that synchronizes first. He wondered if this occurs because of the de-duplication feature in Zimbra that also avoids repeatedly delivering email messages with the same message ID number. Cine said that Frederic did not mention which email clients are in use by the users, but generally it is up to each email client to decide on which calendar events they will download, rather than the Zimbra server. He did not think that the de-duplication feature in Zimbra was involved, as that feature only applies to email deliveries. John H. added that most email clients will consider calendar events with the same UID to be the same calendar event, thereby causing the event to be displayed only once within the email client, even if it appears on multiple shared calendars on the server-side. He said that for ActiveSync clients, it is up to the client to decide on how to display calendar events with the same UID, as either a single event, or multiple events.

Non-Responsive Mailboxd Process and AWS Storage Buckets
Mark S. shared that he recently experienced an issue with one of his Zimbra mailbox servers where none of the users could access their mailboxes, but the mailboxd processes and its dependencies were running with a load of 120%. After a restart of the mailboxd and related services, users still could not access their mailboxes. With Zimbra Support’s assistance, the issue was pinpointed to a problem with mailboxd accessing the AWS storage buckets containing his Zimbra server’s disk volumes. He said that when using AWS storage buckets as Zimbra volumes, he used to be able to create a primary/secondary volume without also needing to create a logical representation in Zextras of the external AWS S3 storage bucket. But, he discovered that now this is required. Cine said that about one year ago, the Zimbra Administration UI changed to add support for some updates to the supported volume types, but the Zextras back-end CLI did not. He said that it should now no longer be possible to create a Zimbra volume without a corresponding AWS S3 bucket. When using AWS buckets for Zimbra volumes, Cine recommended running these CLI commands:

  • “zxsuite hsm getAllVolumes” to get the bucketConfigurationId value, then run:
  • "zxsuite hsm listBuckets” to see the actual bucketConfigurationId for your actual buckets.
  • If your primary or secondary storage volume references a non-existent bucket ID, you may need to run “zxsuite hsm doUpdateVolume …” to fix.
Using Smart Hosts In Zimbra To Manage Outbound Email Routing
Noah P. re-visited a topic from the November 10th Zeta Alliance call ( viewtopic.php?f=9&t=68942#p299710 ) related to controlling SMTP mail flow in Zimbra per domain. He said he had been continuing to experiment with this capability by working with using the Zimbra Smart Hosts feature to attempt to direct mail per domain through specific Zimbra MTAs. Mark S. suggested that Noah should use the “zimbraSmtpHostname” setting per domain for this purpose, but Noah said this setting only works for users who access their mailboxes with the SOAP clients, such as the Zimbra Connector for Outlook and ActiveSync. Noah has observed that the Zimbra Web Client, SMTP (IMAP/POP) clients, mailbox forwarders, and distribution lists still continue to use the Zimbra global MTA setting, ignoring the per domain “zimbraSmtpHostname” setting. Cine suggested using Postfix’s “sender_dependent_relayhost_maps” attribute in addition to the “zimbraSmtpHostname” setting to help ensure consistency for each user’s email client use case. John H. suggested that Noah should also create a Zimbra request for enhancement to make this capability part of Zimbra’s official features.

“Host or domain name not found” Errors During Zimbra Server Migration
Matthew F. said that he is working on a customer migration from an old to a new Zimbra server version. He said that after a mailbox is moved from the old to the new server, the LMTP server address for the mailbox, that Zimbra uses for mail delivery, is updated to the new server’s fully qualified domain name (FQDN) as expected, but email deliveries sent from mailboxes on the old server to the mailbox on the new server result in “status=bounced (Host or domain name not found. Name service error for name=xxxx type=A: Host not found)” error messages in mailbox.log. He found that after moving a mailbox to the new Zimbra server, and changing the LMTP FQDN for a mailbox to an IP address, this then allows for email to be delivered normally. Noah P. wondered if Zimbra may be checking the server’s local /etc/hosts file before using the DNS resolver configured for the server, and the /etc/hosts file contains an incorrect entry for the FQDN of the new server. Mark S. said that he worked with a customer that had a multi-homed Zimbra server, with one network interface assigned to a public IP address, and another assigned to a VPN. He found it very tricky to get mail routed correctly with this setup and suggested using Postfix’s “lmtp=native” setting. He said that without this setting, Postfix avoided using the /etc/hosts file for look-ups and always used the DNS resolver configured for the server. Cine suggested that Matthew take a look at using dnsmasq as it makes these types of scenarios much easier. Mark S. suggested taking a look at his dnsmasq how-to ( ... ion-guide/ ) and said that dnsmasq is beneficial since it only answers DNS queries for records it is specifically configured to answer, and passes all other queries through to the server’s regular DNS resolver. Noah P. also suggested the Zimbra command: “zmlocalconfig -e postfix_lmtp_host_lookup=native” which Matthew said he currently has enabled. Cine added that using the /etc/nsswitch.conf file to set the order in which DNS resolvers are used may help, such as this configuration value: “hosts: files dns”. Mark S. said that this page ( ) maps Postfix configuration settings to Zimbra-equivalent settings may be of help too. Noah P. said that Matthew might be looking for this Zimbra setting too: “zimbraMtaLmtpHostLookup”, which can be described from the CLI using: “zmprov desc -a zimbraMtaLmtpHostLookup”. Matthew F. said he currently has this setting configured: “zimbraMtaLmtpHostLookup: dns”.

Randy Leiker
Skyway Networks, LLC

Re: January 2021 Zeta Alliance Weekly Call Summaries

Posted: Sat Jan 30, 2021 9:14 pm
by rleiker
Hello Zimbra Community,

Here is a summary of this week’s conference call. A few brief reminders:

January 26, 2021

Readiness Of New Zimbra Video Server
Mark S. asked, with the release on Monday of 8.8.15 Patch 18 and 9.0 Patch 11, how stable is the new Zimbra Video Server, even though it is currently labeled as in beta? Cine said that Zextras has been using the Video Server internally for a couple of months and that the current version allows for only one Video Server to be installed for either a Zimbra cluster or a Zimbra standalone installation. He explained that it comes pre-configured with many codecs out of the box, so very little configuration tweaking, if any, is needed. It also eliminates the need for a separate STUN/TURN server, as was often needed for Zimbra Connect previously. Without a Video Server, Zimbra Connect can handle up to 5 participants in a video call, since each caller will have 4 incoming and 4 outgoing video streams. With a Video Server, each caller has only 1 incoming and 1 outgoing video stream to the Video Server (typically about 200 Kbps per stream), so bandwidth usage is greatly reduced, and the maximum number of participants in a call is limited only by the hardware available on the Video Server. Mark S. asked, if you already have a TURN server setup with Zimbra Connect, what configuration needs to be done on the Zimbra mailbox server to start using a Zimbra Video Server? Cine said that setup information for the Video Server is available at ... erver.html , but the beta version of the Video Server should only be setup on a per-domain basis using the Zextras CLI (command line interface) in Zimbra, rather than for an entire Zimbra mailbox server. The beta version of the Video Server also requires that a domain cannot have mailboxes spread across multiple Zimbra mailbox servers. This limitation will be removed with the upcoming general availability release of the Video Server.

Readiness Of New OpenSSL, Nginx, and Postfix Versions
Mark S. asked, how stable are the new OpenSSL, Nginx, and Postfix beta versions in the latest Zimbra patches? John H. said that they have been in beta for about 2 months and that it should be safe to upgrade a small Zimbra installation for testing, but reiterated that each is still considered in beta, so it is not yet recommended for widespread production use.

Zimbra Support for Ubuntu 20.04.1 LTS
Mark S. asked about updates on the availability of Zimbra support for Ubuntu 20.04.1 LTS support. John E. said there will be a Zimbra blog post coming out about it being completed during first half of 2021. He added there is also a new blog post about the status of CentOS support: ... ironments/

Experiences With Zimbra Cloud
John W. (Xmission) shared his experiences with selling Zimbra Cloud. He said that while things initially were a bit of a bumpy road, all is fine now in Zimbra Cloud and that to Synacor’s credit, they have promptly fixed issues as they arose. He said that if anyone signed up earlier for a Zimbra Cloud trial a few months ago, he suggested signing back up again to give it a second trial. He commented that, as a Zimbra BSP (Business Service Provider) he does not feel as threatened by Zimbra Cloud as he previously did, since there is plenty of space in the market for both on-premises Zimbra (offered by BSPs) and Zimbra Cloud to co-exist. He feels that Zimbra Cloud is a different product that is mass market oriented, that brings Zimbra to the attention of a wider audience, while on-premises Zimbra is easier to cater to individual customer needs and customization.

Mark S. asked if there is robust backup/recovery in Zimbra Cloud as compared to on-premise Zimbra? John W. said his company has not had much experience with backup/recovery in Zimbra Cloud yet to comment. But, he says he really likes the mailbox migration tool in Zimbra Cloud, and finds it works particularly well for migrating mailboxes from G Suite/Gmail, and hopes that the migration tool can be made available in on-premises Zimbra for partners.

Mark S. asked how do you determine when a customer is more suited for Zimbra Cloud versus on-premises Zimbra? John E. said it is largely based on what services you are offering as a Zimbra BSP. Zimbra Cloud is targeted at users who have simpler needs. Mark S. asked, for example, if you have a shipyard of 600 workers, and only a handful of those workers want customized Zimbra features, is this a use case for Zimbra Cloud, and could a BSP split email deliveries for a domain between Zimbra Cloud and on-premises Zimbra? John E. said that a split domain is technically possible, but not supported by Zimbra Cloud currently. John E. said that Zimbra Cloud provides the ability to increase your customer base without needing to scale up your on-premises infrastructure. Marc G. said he cannot understand why, as a BSP, if you have sufficient on-premises Zimbra infrastructure setup, why Zimbra Cloud makes sense. John W. said that if a BSP is running Zimbra 8.8.15 on-premises, and they do not yet have support for the third-party integrations available in the Modern UI in Zimbra 9, that it is easy to switch those customers to Zimbra Cloud, rather than losing them to a competing solution. John E. added that every week there are new updates to the Zimbra Cloud UI and/or the Zimlet integrations included within it.

John W. said that early on, some at Synacor did not have a true understanding of what it means to provide email in the SMB (small/medium business) market. But, as Zimbra Cloud has continued to advance, he feels that it is turning out to be a benefit for BSPs, as it is helping Synacor better understand the SMB market and expectations, and the needs of BSPs serving the SMB market. John E. added that Synacor’s intent is to have most everything that is in Zimbra Cloud available in upcoming versions of Zimbra 9. Marc G. asked how has Zimbra Cloud helped Xmission, such as selling Zimbra to a certain demographic of customers? John W. said it was too early yet to answer this question, but said that Xmission has plans to begin a renewed Zimbra Cloud marketing campaign soon. He also commented that Xmission positions Zimbra Cloud with support sold as an add-on option, while their Zimbra on-premises offering is sold with full support included.

Zimbra Bug Bounty Program
John W. and Mark G. commented that they are still seeing some of their Zimbra on-premises customers leaving for Office 365, but nowadays they hardly ever see anyone leaving for Google’s G Suite. Randy L. said that there has been a steady stream of security incidents in the media about the Office 365 platform and that it never hurts to remind Zimbra customers contemplating Office 365 email hosting of this track record. John E. said that to help bolster Zimbra security further, Zimbra has become involved in a bug bounty program for proactively finding and fixing any yet unknown security issues in Zimbra. Zimbra is participating in this bug bounty program:

Randy Leiker
Skyway Networks, LLC