User shibi encountered a Net::ReadTimeout error while configuring Discourse to send emails via Outlook’s SMTP server (smtp.office365.com:587), despite successful telnet connectivity. After testing with mail-tester.com, the error persisted, and no standard solution was available — prompting a recommendation to report it to meta.discourse.org. italo clarified that Outlook does not support transactional emails required by Discourse and pointed to the official email setup guide for compatible services. shibi asked if manual account creation or fetching activation URLs could bypass email requirements, but ultimately shibi resolved the issue by switching to a different mail server that supports transactional emails, which now works fine. The discussion highlights the importance of using transactional email services compatible with Discourse’s SMTP requirements, rather than consumer email providers like Outlook.
I am using outlook account config for email config
Server: smtp.office365.com
Port: 587
The telnet is working from local
but discourse is throwing error Net::ReadTimeout or
Is there is anything I need to do ? or there way to local host mail daemon ?
==================== MAIL TEST ====================
For a robust test, get an address from http://www.mail-tester.com/
Or just send a test message to yourself.
Email address for mail test? (‘n’ to skip) [mail@mail.com]:
Sending mail to mail@mail.com. . .
Testing sending to mail@mail.com using smtp.office365.com:587, username:mail@mail.com with plain auth.
======================================== ERROR ========================================
UNEXPECTED ERROR
Net::ReadTimeout
====================================== SOLUTION =======================================
This is not a common error. No recommended solution exists!
Replacing: SMTP_PASSWORD
Replacing: LETSENCRYPT_ACCOUNT_EMAIL
Replacing: DEVELOPER_EMAILS
Replacing: DISCOURSE_DB_PASSWORD
Replacing: Sending mail to
==================== DONE! ====================
root@discourse:/var/discourse# telnet smtp.office365.com 587
Trying 52.96.88.98…
Connected to MNZ-efz.ms-acdc.office.com.
Escape character is ‘^]’.
220 MN2PR14CA0028.outlook.office365.com Microsoft ESMTP MAIL Service ready at Mon, 24 Jul 2023 21:20:54 +0000
mail@mail.com should be replaced by email
Hello again, Shibi! 
Unfortunately is not possible to use Outlook as it does not support transactional emails. Check this tutorial with a list of recommended email services.
. Any alternatives without using email , eg creating accounts manually . or fetch the activation url
I have found mail server which support this and its working fine