Problems sending mails to different domains

[Marcosebas]

Dear All,

Recently, I am having problems to send emails from my domain. I checked the RBLs of my domain in mxtoolbox and is completely clean, same with Cisco Talos I have a good mark and in Cyren I am not considered an spammer. However, I am facing some issues with senderscore. I contacted them and they told me they use the 4 main mailbox which are Gmail, Yahoo, Hotmail and AOL. To Gmail and Yahoo I am sending mails without problems. To Hotmail my emails are not arriving at all, not even to junk. AOL I didn't test because noone use it in here.

I was tracing my mails and they are going out of my system, but simply they are not arriving to their destination in many cases.

Please, any tip, advice about what can I do would be much appreciated. i give support to other 3 systems without problems, but in this one I simply don't know what else to do. i checked RBLs, ny DNS, traced the messages, I have DKIM, SPF and DMARCS correctly configured, etc.

I am using ZCS 8.6.

Regards,

Marco

[JDunphy]

This is another required hoop from microsoft related stuff like hotmail, live, etc. Register your ip ranges of your mail server[s]. About an hour before they have your range after you register and you should be good.
https://postmaster.live.com/snds/ ... If that doesn't work, open up a ticket with them with the new account you created to register your address space.

[JDunphy]

Forgot this one too. https://sender.office.com/ ... They could be more but those generally do it.

[Marcosebas]

Forgot this one too. https://sender.office.com/ ... They could be more but those generally do it.

Hi Dunphy,

Thank you for your suggestion, but that is not my problem. I already did that and couple of weeks ago I was sending mails to Outlook without any issues. Currently, my problem is not only that my emails are not arriving to hotmail/outlook, but also to other domains. I checked RBLs, Cisco Talos, Cyren and others and I am clean.

I would like to know if there is any possibility to check and trace my mails and see where they are being stopped.

Regards,

Marco

[phoenix]

You could check your Zimbra log files to see if it's making a connection to the recipient server.

[Marcosebas]

You could check your Zimbra log files to see if it's making a connection to the recipient server.

Hi Bill thank you for your answer and time. It is making connection and leaving my system to the Internet. However, somewhere is getting lost or is being stopped. AS said before I have many domains where I have problems to deliver, but to others I don't have issues to deliver.

[phoenix]

If it is making a connection to the remote server implies that the message was delivered to that server, if that's the case then the only course of action is to check with the admin of that server if it's been received and what happened to it. AFAIK, there is nothing else you can do and the fact that your server connected to the remote server implies that it was delivered to their system(s). The only thing I can think of would be any problems with SPF, DKIM, DMARC if you have those deployed the recipients may be discarding them.

Is this a new problem or has it been happening for a while? Have you had problems delivering to these other domains before and is it always the same domains that have the problem? As far as the DMKI etc. settings, have you checked them by sending a test email to a google mail account, if you do that the 'show original' would give details of their status (but I'm sure you know this already )?

[Marcosebas]

If it is making a connection to the remote server implies that the message was delivered to that server, if that's the case then the only course of action is to check with the admin of that server if it's been received and what happened to it. AFAIK, there is nothing else you can do and the fact that your server connected to the remote server implies that it was delivered to their system(s). The only thing I can think of would be any problems with SPF, DKIM, DMARC if you have those deployed the recipients may be discarding them.

Is this a new problem or has it been happening for a while? Have you had problems delivering to these other domains before and is it always the same domains that have the problem? As far as the DMKI etc. settings, have you checked them by sending a test email to a google mail account, if you do that the 'show original' would give details of their status (but I'm sure you know this already )?

Hi Bill,

Yes the DKIM, DMARCS and SPF are correct. I was sending mails without issues, but this problem started couple of days ago (around 2 weeks) that is why I try to trace the packages somehow. For example to Gmail, yahoo or my other corporative mail arrives without issues, but to other domains such as Outlook or other companies my mails never arrive even not to spam folder. They simply get lost.

[JDunphy]

You seem pretty sure about your DMARC, SPF, and DKIM ... Sounds like you have checked and verified them. This link https://dmarcian.com/ under tools is what I use as the inspectors are pretty good. Sometimes, email works and then the provider decide to enforce some of those settings you have listed. But you don't have any concerns with them so this seems really odd given you are also not on any blacklists and you have positive confirmation of delivery via the logs. I always use google myself to view email I send as the first test to make sure they can validate our signatures and that the ip's addresses are correct and nothing seems odd in the envelope.

Note: I noticed under detail for my domains on March 20 with dmarcian I had 25 DMARC violations from mail30c40.carrierzone.com for my personal domain that someone attempted to forge. I have rua and ruf defined in our DMARC records to track this stuff and Yahoo rejected these emails as I had requested and notified us.

Not sure how else to help. You appear to be doing everything I would have done.

[Marcosebas]

Y es, but for my boss it simply doesnt work and I need to fix it