email set up

[#1]

New computer with 365 and Windows 11. Same antivirus as on old computer. Finally set up email addresses in outlook. Had to use POP rather than IMAP but no worries but each time I open outlook I get a warning, "The server you are connected to is using a security certificate that cannot be verified. The target principal name is incorrect". I ignore it but it's annoying. Anyone have any ideas on a permanent fix? 

[#2]

Hi there,

Sorry for the delay, do you happen to have your emails setup on any other devices which don't use Outlook?

I'm wanting to know if this issue is specific to Outlook or affects other email clients. 

[#3]

I started setting up my emails on my new computer using "Mail" until I realised that it wasn't "outlook" (doh!). Mail didn't throw up any strange messages but it wasn't so versatile and as I'd exported emails from Outlook on my old computer and wanted to import them now, I began setup with Outlook, getting the message I reported earlier. 

[#4]

Ah really odd.

Is the version of Outlook the same with what was on your old computer? 

[#5]

Yes, so far as I'm aware. Certainly they're both part of 365. 

[#6]

Ah not sure what the issue could be but hopefully someone from the Community might be able to help further. 

[#7]

This is a common issue!

Outlook "guesses" at what the pop3 / IMAP / SMTP server names are.  Whilst it might guess at something which works, what works and what is in the security certificates might not be the same.

There is no good reason why IMAP will not work with Outlook as downloaded from Office365 - you did not advise what issue you encountered, but my guess would be that the server details guessed by Outlook were simply wrong.

First thing to consider is that your email address is @account.plus.com and that is what Outlook will use to guess the server names along the lines of mail.account.plus.com and smtp.account.plus.com

The correct settings can be found here - How to set up Plusnet email | Help | Plusnet

Notes of clarification

1. SMTP server is relay. not smtp. as guessed by Outlook, which will work, but is not in the security certificate
2. SMTP should use port 587 not port 25
3. SMTP encryption is STARTTLS
4. IMAP and POP3 encryption is TLS/SSL

Hope that helps.

[#8]

Finally got round to giving this another go. I still couldn't set up IMAP but having set up POP I was able to go into the server settings and alter them as recommended. It works. No more warning messages. Thank you for your help.