Verification emails not working properly

[Guest]

Hi! I've got a v4.2.0 server running on MongoDB.

I've set up my SMTP server using FastMail, and the validation emails all seem to be working fine, but when sending verification emails, I see the following in the logs:

Mar 29 23:09:03 host002.local env[129031]: 2025-03-29T23:09:03.466Z [4567/129031] - error: [user.create] Validation email failed to send
Mar 29 23:09:03 host002.local env[129031]: [emailer.send] Error: Message failed: 551 5.7.1 Not authorised to send from this header address
Mar 29 23:09:03 host002.local env[129031]:     at SMTPConnection._formatError (/home/nodebb/nodebb/node_modules/nodemailer/lib/smtp-connection/index.js:809:19)
Mar 29 23:09:03 host002.local env[129031]:     at SMTPConnection._actionSMTPStream (/home/nodebb/nodebb/node_modules/nodemailer/lib/smtp-connection/index.js:1730:34)
Mar 29 23:09:03 host002.local env[129031]:     at SMTPConnection. (/home/nodebb/nodebb/node_modules/nodemailer/lib/smtp-connection/index.js:1198:22)
Mar 29 23:09:03 host002.local env[129031]:     at SMTPConnection._processResponse (/home/nodebb/nodebb/node_modules/nodemailer/lib/smtp-connection/index.js:993:20)
Mar 29 23:09:03 host002.local env[129031]:     at SMTPConnection._onData (/home/nodebb/nodebb/node_modules/nodemailer/lib/smtp-connection/index.js:774:14)
Mar 29 23:09:03 host002.local env[129031]:     at SMTPConnection._onSocketData (/home/nodebb/nodebb/node_modules/nodemailer/lib/smtp-connection/index.js:195:44)
Mar 29 23:09:03 host002.local env[129031]:     at TLSSocket.emit (node:events:518:28)
Mar 29 23:09:03 host002.local env[129031]:     at addChunk (node:internal/streams/readable:561:12)
Mar 29 23:09:03 host002.local env[129031]:     at readableAddChunkPushByteMode (node:internal/streams/readable:512:3)
Mar 29 23:09:03 host002.local env[129031]:     at Readable.push (node:internal/streams/readable:392:5)
Mar 29 23:09:22 host002.local env[129031]:   started

I'm not sure how to drill into this - why would it work fine sending test emails, including verification ones, but then actual verification emails just fail?

Thanks!

[astro-what@community.nodebb.org]

Are you by chance using an email provider with a set user account@domain specific to them (like Hotmail or Google) and then using a different domain address for your website?
Not unusual if so as most do not allow relaying other domains through an account unless it is specifically allowed.

[Guest]

Yes, that might be it! I'll see if I'm able to create a login for the proper domain, great idea!

[Guest]

Silly thing - it looks like the problem was that I changed which domain the emailer was sending from (moved to forums., but forgot to set it to that in the email settings, and didn't notice the discrepancy much after because the test email works fine. It's working great now after fixing that. Thanks for the idea to check the login domain! I did not have to switch that out for Fastmail after all.