Plus addressing on IMAP email not appearing on Windows Outlook

[Magicbean]

Apologies if this has been answered but I can't find this specific issue addressed. (Some of the threads are very old, the others seem to be about POP3 emails).

I am trying to send emails to an IMAP email and am using Windows 10 Pro and Windows 11 Pro with Microsoft 365 desktop email clients to access the emails.. The email is managed in a domain that I run and manage through cPanel.

The plus-addressing seems to be fine as far as cPanel is concerned. The specific problem I have is that the Outlook desktop app (from Microsoft 365) doesn't display the plus-addressing folders.

In Outlook, the folders show up in the 'subscribed folders' list but not in the Email folders list even though they claim to be 'subscribed'. I know the emails are being sent and received correctly because I can see them in other email clients (iPhone mail, Thunderbird etc) and in the Horde email client in cPanel. It's just Outlook which refuses to display the folders.

Any clues?

Thank you.

 

[cPRex]

Hey there! We've had other users report similar behavior when using Outlook. They reported they needed to create filters in order for them to show up how they are expecting, and how other clients do automatically. There are more details on there here:

PLUS Addressing Not Working

I see threads that are 6 years old saying that PLUS addressing isn't supported in cpanel. I wonder what current status is as I see more recent information that says it is. I'm not being successful with it and need to make it work if at all possible.

forums.cpanel.net

Can you try that and see if that gets things working?

 

[Magicbean]

The link you replied with is exactly what I referred to in my original post. It is about how to get it working for POP3 emails. This is IMAP, it is supposed to just work. Well, the cPanel side does.

I gave filters a go but it is unsatisfactory. A large part of the point of the plus-generated folders is that you don't have to reconfigure your emails when you give out a new plus-address email.

There is one way I can make it sort-of-nearly-work:

If I know in advance that I want to spontaneously give out a new plus-addressed email, I can:
1) Go in to cPanel or an email client and create a folder 'couldbejunk' for example.
2) Create a filter in cPanel that picks up emails to [email protected] and moves it to the couldbejunk folder. (If I do it in the email client, I would have to do it in all email clients otherwise whether it works or not depends on which client is running).

This works (except that my system then takes it out of there and moves it immediately to 'Spam' even with all other filtering disabled and Spam filters disabled). If you disable the 'automatically create folders' option, the emails land correctly in the inbox.

To be honest, it doesn't seem good enough to be useful. I don't want have to guess what email address I might give out in advance and create folders and filters for each one, I just want Outlook to display the folders that are already created. And I want the plus-addressed emails to end up in individual folders I can see (but not the same folder for every plus-addressed email). In other words..... exactly what plus-addressing is supposed to be doing.

I noticed that there is something different about the plus-one folders. If you look at them in the cPanel Horde email client, they are in italics which suggests they are not regular folders?


The question is, why doesn't Outlook (specifically on Windows) display the folders? (Even Outlook on Microsoft 365 for MacOS works OK!)

Or .....why is cPanel generating plus-addressing folders that Outlook on Windows refuses to display?

 

[cPRex]

I've been playing with this a bit on my end and I do see this working well on Mac, webmail, only showing up in the Outlook Windows client. Since the issue doesn't appear to be caused on the server side, there aren't any changes we can make, as any changes would likely disrupt the other tools. My only advice in this particular instance would be to use the email client that works best for your users.

 

[Magicbean]

I've been playing with this a bit on my end and I do see this working well on Mac, webmail, only showing up in the Outlook Windows client. Since the issue doesn't appear to be caused on the server side, there aren't any changes we can make, as any changes would likely disrupt the other tools. My only advice in this particular instance would be to use the email client that works best for your users.

Yes, it looks like the problem is entirely in Outlook for Windows. Every other email client on seem to show these automatically generated folders (Including Outlook on Mac). I have raised a support ticket with Microsoft but I expect they will suggest something unhelpful like re-installing Windows.
Thanks anyway.

 

[cPRex]

I'm sorry there isn't more I can do on my end for this one. I did have our team check, but since things are working in all other clients we decided at this point to not try and adjust anything within the dovecot settings, as that could break existing functions.