topic Re: Email send failed on certificate error - fixed for me in Email

Email send failed on certificate error - fixed for me

SimonC — Thu, 27 Aug 2026 12:24:23 GMT

Thought I’d put a one-line solution for the less technically minded like me.

I’m a Plusnet / Greenby user accessing email on Android through K-9 Mail app for a few years now with no issues.

Sending emails failed this week with certificate error. Trawling here gives lots of multi-post multi-page answers full of wordy detail that I barely followed but I managed to extract:

Go to Outgoing Server Settings in your mail app.

Change “relay.plus.net” to “mail.enmail.co”

That’s it.

No, I don’t know what “mail.enmail.co” is, I just copied it from another thread. If it doesn’t work for you you’ll have to look for proper experts.

Good luck!

Simon

Re: Email send failed on certificate error - fixed for me

Townman — Thu, 27 Aug 2026 13:29:13 GMT

For clarity. This is not a fix - it is a circumvention.

In scenarios where email client auto-configuration selects the servers, this might not work / stick.

It is only going to work for those who have their email migrated to Greenby.

Re: Email send failed on certificate error - fixed for me

PhilipHeyes — Thu, 27 Aug 2026 13:31:19 GMT

I am not sure an additional thread adds value.

Re: Email send failed on certificate error - fixed for me

SimonC — Thu, 27 Aug 2026 14:25:11 GMT

It would have saved me an hour wading through stuff I didn't understand for the suggestion buried deep somewhere.

Re: Email send failed on certificate error - fixed for me

PhilipHeyes — Thu, 27 Aug 2026 14:36:37 GMT

One hour, poor you !