Outlook Android app cannot login IMAP email server.

AWESOME reply!

It explains all I ever wanted to know and I appreciate it!

Thank you!

R

Don't know if that helps you on this topic, but I had the same issue and was trying out absurd scenarios just to find out that STARTTLS for IMAP in Outlook App is not working at all.

Direct TLS via 993 works fine.

The joke is that STARTTLS for submission/smtp works fine. That's really absurd, but I gave up trying it with 143 using this app, since 993 seems to be more widely adopted by many MSPs anyway and some even disabled the use of 143/IMAP. Check your MSPs DNS SRV records for _imap and _imaps.

I'm not sure which RFC Microsoft thinks it is following here, but STARTTLS was supposed to replace direct TLS as far as I understood in the past. After the IETF has completely deprecated any plaintext authentication, the recommendation was to use implicit TLS. Seems like Microsoft changed its path.

RFC 8314 seems to recommend implicit TLS throughout any communication between the MUA and MSP, with the exception that _submission was adopted due to port configuration on existing MSPs using port 25. For an MTA it is understandable, because some vendors transferring mails dont know (except when using DANE or MTA/STS) if the other side supports TLS at all. That's why there is a choice to use plain mail transfer or STARTTLS-upgrade the transfer. Some MSPs used 25 for MUAs, growing numbers use 587 today.

Coming back to above mentioned lines, for IMAP, with RFC8314, deprecation of plaintext and the recommendation to use implicit TLS, it makes sense to disable STARTTLS.

Unfortunately Microsoft didnt let the users any choice to amend this. This may go along with the 2019' approval of the Outlook App to be used by the Pentagon Department of Defense.

That's why, in my opinion, Microsoft does not consider this a bug and does not respond to "bug requests".

What you can do is to try entering your MSPs connection details manually, i.e. smtp-host, user,pass, but IMAP with Port 993 and SMTP with Port 587. This may then work as it did for me.

Unfortunately, the Rising Sun refuses to Rise - it keeps on wanning!

I guess Microsoft is focused solely on supporting business applications, like Exchange mail. IMAP is simply not worth it to them. Judging by the growth of their cloud services and the stock price, seems like they are right.

I use Outlook for my business email and Mail (Google's Android app) for both Yahoo and IMAP accounts

We (hubbie and I) are experienced at being retired. During professional working years MS Office was go to app for me and it was natural to continue that with 365 after retirement. Thx for your input. I too had that 'hacked' feeling which is NOT fun. (Listening MS? No not Multiple Sclerosis, MicroSoft... don't ask me the difference!!! LOL!)

Hubbie finally resolved issue for us by uninstalling, restarting Samsung, re-installing which included adding all our email addresses...ugh, I am grateful that he did that. It took 3 attempts, so be patient and have all that secret stuff in front of you!

So one and all, the work around is to un-install, restart, re-install, re-add main accounts and jump up and down 7 times, turn around 11 times and face the rising sun! Hoping that all goes well!!!

(Well, I may have gone too far with that, but it sure seems that way. So Much for AI....whose IQ is in single digits! LOL!)

Good luck all!!!