Does blocked ports (25, 465, and 587) affect Nextcloud mail ?
Unexpected error during account creation
I've read that Linode is blocking ports 25, 465, and 587 by default. Do I need to unlock these ? Thanks for your time :)
If Nextcloud (something I know nothing about…so if) is trying to phone home by sending a test email to one of their servers as part of account creation, then yes. IMAP uses ports 143 (cleartext) and 993 (encrypted) so wouldn't be affected by the Linode block. Ditto for POP3 (110 clear and 995 encrypted).