Hey Karl, 

Thanks for posting to the community. You are right this likely isn't a SmarterMail problem. It's most likely that these clients migrated over from exchange to SmarterMail and kept their local outlook profile. When this happens Outlook will sometimes try to send to users using a local id that doesn't exist on SmarterMail. The easiest way to fix this is to completely remove the profile from Outlook and then resync. Please follow this guide. https://portal.smartertools.com/kb/a3487/how-to-thoroughly-replace-your-mapi-account.aspx

Please also double-check the users synced contacts in Webmail and ensure that they all go to valid addresses. 

Please let me know if this helps. 

Kind Regards, 

I am surprised my Zach's post, because he is mistaken.   This is an issue under active investigation.   My ticket on this topic was added to one that was already open.

Here is the problem:   The user has an autocomplete entry,  which should be interpreted as a friendly name and email address:

"first last" <user@domain>

Instead it is being interpreted as an invalid email address with embedded spaces: 

<first last user@domain>

The problem is clearly visible in the logs, where friendly names do not appear.    You are correct that the problem can be resolved by deleting the problem autocomplete entry or emptying the autocomplete folder completely.   

Obviously, this could be a Microsoft issue or a SmarterMail issue.   We can hope that it is a SmarterMail issue, or that SmarterMail can find a workaround to a Microsoft issue, so that we obtain a solution sooner rather than later.

@Zack, the users affected were previously using EAS connecting to Smartermail and it still existed as a Outlook profile and a new MAPI profile was created. 

Smartermail has been in use the whole time, there has not been a transfer from exchange.If it helps it seems that the problem happens most on replies to multiple recipients, it is intermittent. The last reported incident the user was only able to receive emails on his phone when he was outside the plant/office or connected to cell service. the Outlook would only get emails most of the time when forcing a folder update.
I did a clean full profile and folder deletion and recreated the MAPI profile and his emails are working on both the phone and the Outlook and as yet no reported "recipient does not exist" errors.

@Douglas, Thanks for that info, good to know i'm not the only one experiencing it. I am assuming that it is only happening between Outlook and Smartermail and not Thunderbird or eM Client?

I have noticed that the corruption or interpreted email is as you describe but i have also seen <first last' user@domain> with a missing ' at the beginning as well as both missing entirely.

This might help investigations to more advanced users https://github.com/stephenegriffin/mfcmapi/releases/tag/21.0.21127.03 but be aware it will brick your whole mail box if misused.

This is a link to backup and accessing and restoring the autocomplete https://www.msoutlook.info/question/backup-and-restore-autocomplete

I did not locate a current community post about this but if there is one please add the link or merge them as necessary.

Hello,

I took a look and there is a dev task for this. I apologize I was mistaken. Thanks for confirming the information regarding deleting the autocomplete as a workaround.

Kind Regards,  

Hi everyone,

I wanted to let you know that this issue has been address in Build 8223. We've received confirmation from a few customers that this has been resolved in their environments. However, if you continue to experience this behavior after upgrading, please submit a new support ticket so we can continue a review within your environment. 

Thank you!