Just spent the past few days installing NC12. Took ages to get the thing secure, ie SSL but it’s all good and my apps are all working etc…
The only thing I can’t get going is the mail server for notifications etc. I have an OC 9 which I have had running for a while so I just copied the settings over to NC12 …
When I try the test email I get an error:
A problem occurred while sending the email. Please revise your settings. (Error: Connection could not be established with host smtp.myMailserveraddress.com [ #0])
I have looked around everywhere for a solution. The mail app for NC12 works very well with the same server info. I guess that the notification SMTP mail and the mail app are different beast otherwise it would have worked?
Is this a large mail provider? They sometimes have additional security features that can make it difficult to use this option (e.g. gmail). But we need more details, just saying it doesn’t work is not enough.
There were some reports earlier but nothing was really related to Nextcloud:
If you have access to the server, you might use the command line to try to login manually. In the past, I had better results by passing mail via sendmail to a small ssmtp-process which then delivers the mails. I would also try different providers, some have just set a few firewall rules or anti-spam settings that prevent you from dropping of such mails.
I know this is an old post, but I was having the same problem and one of the suggestions provided here worked, so I thought it helpful if I updated this thread with that information. What worked for me was changing the Encryption from SSL/TLS (even though that’s what all my other applications wanted) to STARTTLS.