I host a server on Google Cloud with Protonmail Bridge running in the background. I am still new at working with CiviCRM 5.26.1 and PHP. I can successfully send emails via Drupal usinig the SMTP module but with CiviCRM I receive this error when I send a test email:

authentication failure [SMTP: STARTTLS failed (code: 220, response: Ready to start TLS)]

In the Bridge Configuration Guide, an exception has to be set on Thunderbird.

Now, according to this solution that would seem to solve my problem : SMTP connection failing problem, I don't have the same structure when I open the /Net/SMTP.php file.

Note: This exception is needed for Protonmail Bridge.

  • welcome to CiviCRM SE - well explained question - hopefully some one with mailing experience can answer soon
    – petednz - fuzion
    Jun 16, 2020 at 3:46

1 Answer 1


Civicrm has changed how it's including the PEAR library - it was previously including a patched version - however this was updated in https://github.com/civicrm/civicrm-core/commit/a6a0ff13d2a155ad962529595dceaef728116f96# to improve maintainability

I believe if you want to apply the fix from SMTP connection failing problem

you will now find the required file in vendor/pear/net_smtp/Net/SMTP.php

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.