Occasional SSLCertificationError when sending registration email

An SSLCertificationError sometimes occurs after a user enters an invalid password on their first registration attempt. If the subsequent registration succeeds, the user can log in, but the confirmation email fails to send due to this SSL error.

Start by reproducing the registration flow with an invalid password followed by a successful attempt, then trace where the confirmation email is sent and where SSLCertificationError is raised. Done means a successful subsequent registration reliably sends the confirmation email without the SSL error.

Written by the indexing model from the issue text.