Zimbra 10.1.10 Released - Please Post Your Patch/Upgrade Results Here

[adrian.gibanel.btactic]

1. when forwarding an email (or sending, but forwarding seem more common the triggering of the issue), the end users on iOS with Active Sync will receive a message saying "Cannot Send Mail: An error occurred while delivering this message." with "OK" being the only option to this notification. The email will how ever go, once the "OK" button is pressed on. (see attached picture)

I happen to have a similar problem with some Android apps (in my case forwarded emails are never sent) since ZCS NE 10.1.9.
Can you check sync.log contents to see if

Code: Select all

SmartForward is not supported in the protocol version specified.

appears in the log when this forward issue happens?

In any case open an NE case so that Zimbra takes a look at it.

[dapa6]

Hello

have you managed to identify the issue with zimbra support and resolve it?

thanks.

Greetings,

so I note the latest patch for Zimbra 10, released on the 18th of July 2025, says the following, amongst much else.

"ZCO / ActiveSync / EWS
Multiple enhancements and fixes in calendaring, sharing, delegation, and mail syncing with Outlook and other Apps."

I run a Zimbra 10.1.10 Server with Ubuntu 22.04, all updated to the latest, and have noticed from clients in UK, Italy and Spain, that:

1. when forwarding an email (or sending, but forwarding seem more common the triggering of the issue), the end users on iOS with Active Sync will receive a message saying "Cannot Send Mail: An error occurred while delivering this message." with "OK" being the only option to this notification. The email will how ever go, once the "OK" button is pressed on. (see attached picture)

2. some users have also noted that emails are coming in and leaving, extremely slow — and again, those users are users using Active Sync installed on their Microsoft Outlook applications on their Windows PC computers.

NOTE
This does not seem to affect users on IMAP.
Users are telling me this started four days ago - I had the server patched on Sunday past, aka four days ago.
I have not had anybody on Android telling me this is an issue for them.

best wishes,

miguel

[L. Mark Stone]

The “Cannot send email” over ActiveSync is a known issue. I opened a Support Case and have sent Zimbra lots of logs and details.

Since it is not reproducible on demand I suspect it’s a bit of a challenge to find the root cause.

As soon as I hear something I’ll post an update here.

[BradC]

Cool. We'll put the brakes on upgrading from 10.1.9 until this is resolved.

This is why we let others upgrade first

[yogesh.dasi]

@mafiabusiness Could you share the iOs version being used where this error shows up?

[wentum]

I unfortunately can confirm that forwarding emails via ActiveSync from Apple devices is broken since 10.1.10.
IOs is 18.5 (22F76).
So better stay away for now...

Regards
Joerg

[adrian.gibanel.btactic]

The “Cannot send email” over ActiveSync is a known issue. I opened a Support Case and have sent Zimbra lots of logs and details.

Since it is not reproducible on demand I suspect it’s a bit of a challenge to find the root cause.

So... Aren't you finding this issue only when an email is forwarded?

[liverpoolfcfan]

The “Cannot send email” over ActiveSync is a known issue. I opened a Support Case and have sent Zimbra lots of logs and details.

Since it is not reproducible on demand I suspect it’s a bit of a challenge to find the root cause.

As soon as I hear something I’ll post an update here.

1. when forwarding an email (or sending, but forwarding seem more common the triggering of the issue), the end users on iOS with Active Sync will receive a message saying "Cannot Send Mail: An error occurred while delivering this message." with "OK" being the only option to this notification. The email will how ever go, once the "OK" button is pressed on. (see attached picture)

I happen to have a similar problem with some Android apps (in my case forwarded emails are never sent) since ZCS NE 10.1.9.
Can you check sync.log contents to see if

Code: Select all

SmartForward is not supported in the protocol version specified.

appears in the log when this forward issue happens?

In any case open an NE case so that Zimbra takes a look at it.

That sounds to me like an unintended result/side-effect of the suggestion to downgrade the ActiveSync support level for devices.

SmartForward was only introduced by ActiveSync Protocol 14.0 - Some Apps ignore the Server Supported Protocols advertised by the server and just fire their latest commands regardless.

A good example of this is the last few iOS Mail client releases have started sending the "Find" command to servers that advertise Protocol Support for up to 14.1 whereas the Find command was only introduced by Protocol 16.1

A good place to start with any reported issues would be to look at any settings that might affect the Protocol levels - For example

Code: Select all

[zimbra@mail ~]$ zmprov ga <affected account> | grep -i protocol
zimbraMobileForceProtocol25: FALSE
zimbraMobileForceSamsungProtocol25: FALSE
[zimbra@mail ~]$

particularly the zimbraMobileForceProtocol25 one.

You could possibly have a scenario where someone had an older Android phone that required forcing the 2.5 protocol on their account but they have now switched to using an iPhone or to a different mail app that ignores the limitation.

[adrian.gibanel.btactic]

SmartForward was only introduced by ActiveSync Protocol 14.0 - Some Apps ignore the Server Supported Protocols advertised by the server and just fire their latest commands regardless.

That's interesting. Why do I find SmartForward in the Activesync Protocol 12.0 spec then?

If I go to: [MS-ASCMD]: Exchange ActiveSync: Command Reference Protocol and I click on the 12.0 version PDF I can see SmartForward command in page 75 of 360.

If EAS 12.0 version supports SmartForward I think that EAS 12.1 should support it too.

You say that SmartForward was introduced by ActiveSync Protocol 14.0... and given your z-push experience you must be right so... I have many questions:

- Have Microsoft messed up their documentation?
- Am I not looking into the right place?
- Having a command in a spec version does not translate to actual Microsoft Exchange Activesync Servers implementing in that same spec version but in a later version instead. Isn't it?

My initial thoughts on this issue is that Zimbra did not implement SmartForward command in Activesync Protocol 12.1 as they should have had. Maybe I need to backtrack on my assumptions.

[liverpoolfcfan]

That's interesting. Why do I find SmartForward in the Activesync Protocol 12.0 spec then?

If I go to: [MS-ASCMD]: Exchange ActiveSync: Command Reference Protocol and I click on the 12.0 version PDF I can see SmartForward command in page 75 of 360.

If you go to the document you referenced, and without changing versions, navigate in the left panel to
Expand
2. Messages
2.2 Message Syntax
2.2.1 Commands
2.2.1.19 SmartForward

You will see the first Element in the Table is the SmartForward element referencing - section 2.2.3.169

Click on it, or navigate to that section in the left panel.

You will see that the SmartForward Element it is only supported in ActiveSync protocols 14 and above.

Edit: Fixed typo