Matthew Meszaros 211650af8d feat: send through every kind of SMTP server (issues #359-#361): negotiate the sign-in method from what the server advertises, preferring CRAM-MD5 then LOGIN then PLAIN, because sending AUTH PLAIN blind was refused by every server that offers only LOGIN, which is Microsoft 365 relays and most appliance relays, and that refusal was reported to the mailbox's owner as a wrong password and deactivated the account; put a deadline on the whole SMTP conversation so a peer that stops answering without closing the connection can no longer park a send goroutine forever, which only the dial was protected against; classify a refusal by its reply code so a permanent 5xx on the sender, the recipient or the message is reported as the rejection it is and not retried four times as though the server were offline, while a 4xx still retries; announce the sender's own domain in EHLO rather than net/smtp's localhost, which relays read as a spam signal; and share one AUTH LOGIN implementation with the notification mailer instead of keeping two copies of the code that handles credentials

2026-09-07 04:19:42 -07:00

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feat: send through every kind of SMTP server (issues #359-#361): negotiate the sign-in method from what the server advertises, preferring CRAM-MD5 then LOGIN then PLAIN, because sending AUTH PLAIN blind was refused by every server that offers only LOGIN, which is Microsoft 365 relays and most appliance relays, and that refusal was reported to the mailbox's owner as a wrong password and deactivated the account; put a deadline on the whole SMTP conversation so a peer that stops answering without closing the connection can no longer park a send goroutine forever, which only the dial was protected against; classify a refusal by its reply code so a permanent 5xx on the sender, the recipient or the message is reported as the rejection it is and not retried four times as though the server were offline, while a 4xx still retries; announce the sender's own domain in EHLO rather than net/smtp's localhost, which relays read as a spam signal; and share one AUTH LOGIN implementation with the notification mailer instead of keeping two copies of the code that handles credentials

2026-09-07 04:19:42 -07:00