Issues on Office365 IMAP

First try updating to the latest test release of MailMate: Hold down ⌥ when clicking “Check Now” in the Software Update preferences pane.

If it still doesn't work then try to hardcoding the port number to 587p.

Sounds strange with the “Junk” folder. Try selecting the “real” junk related folder under SOURCES in the mailbox list and then use “Mailbox ▸ Mailbox Type” to the “Junk” type. Does that help?

Got to the what i think is the latest release following your instructions: "MailMate r5413 is the latest version available—you have r5413."
Also tried changing the port to: 587p

The "Junk" mailbox solution was successful.

Sorry, I missed what the status was here. Does this mean that it is still failing after updating?

Could you upload a new set of logs such that I can see if the behavior is still the same?

Correct, it still did not work post-update.
New logs attached!

Steve A

If its helpful, it looks like Office365 requires TLS for SMTP. Is it possible you're using the native macOS SSL libraries? If so, I'm pretty sure they don't support the latest version of TLS.

Steve A

I'm not sure where you have that TLS information from, but I'm quite sure this is not the problem. I can also connect using openssl which is certainly not state of the art on macOS.

I configured a dummy account to try and make MailMate connect to the SMTP server. I don't seem to have any problems:

22:41:01 Trying to connect to smtp.office365.com on port 587 (CFNetwork) with STARTTLS (required)  
22:41:01 Resolved hostname (smtp.office365.com).  
22:41:01 Successful connection.  
22:41:01 Ready for reading.  
22:41:01 S: 220 HE1P190CA0012.outlook.office365.com Microsoft ESMTP MAIL Service ready at Wed, 13 Sep 2017 22:41:01 +0000

This is what you got:

20:52:48 Trying to connect to smtp.office365.com on port 587p (CFNetwork) with STARTTLS (required)  
20:52:48 Resolved hostname (smtp.office365.com).  
20:52:48 Successful connection.  
20:52:58 Error code: 2

Is your network connection slow or unusual in some way?

What happens if you try the following in a Terminal window:

openssl s_client -connect smtp.office365.com:587 -starttls smtp -crlf

If it connects (as it does for me) then you can close the connection by writing QUIT.

Results of the command you suggested. Not sure if its important but quit was unable to terminate the session, I had to CTRL-C out. I'm not sure if it should have returned more than just "CONNECTED".

$ openssl s_client -connect smtp.office365.com:587 -starttls smtp -crlf
CONNECTED(00000003)
quit
QUIT

Its not a slow connection. Although I think my org does TLS decryption. If that was the issue though I'd hope we'd see failure in the logs for it. Also the openssl s_client test probably would have failed as well.

Thanks for all your help so far!
Steve A

Another quick question:
I've added a second account not attached to our corp account to test if there is an issue with some internal configuration (similar to your dummy account test). However I can't seem to get mailmate to send as this new account/profile. I currently have the dummy account selected in preferences under 'New Message: default account is", but mail still ends up the the 'drafts' of the corp profile (which fails).

If I can get to a state where I can send mail with the dummy profile I think it would shed some light on things here.

Thanks in advance!
Steve A

You should get longer than CONNECTED. The end of the output should be:

---
250 SMTPUTF8

If you are not getting that then I think the issue is something local. Firewall or network issue of some sort?

Dummy account: You need to provide an email address in the account to get the address in the From popup in the Composer. Then MailMate should try the SMTP of the dummy account. It doesn't matter what the address is (since you don't really need to send anything, you just need to see if it can attempt sending at all).

Good catch. Looks like TLS decryption is preventing a full connection.
Thanks for your help!