2018/05/03

Reference links:

• issue on Redmine
• help request on tootsuite@GitHub

Solution

1. You have to restart (or reload?) the SideKiq job, possibly in addition to the web job.
2. Installing Postfix and using these settings works well:

SMTP_SERVER=localhost
SMTP_PORT=25
SMTP_AUTH_METHOD=none
SMTP_OPENSSL_VERIFY_MODE=none

Notes

journalctl -u mastodon-sidekiq | grep smtp yields this:

May 03 11:15:21 tootcat2 bundle[5368]: /home/mastodon/.rbenv/versions/2.5.0/lib/ruby/2.5.0/net/smtp.rb:539:in `initialize'
May 03 11:15:21 tootcat2 bundle[5368]: /home/mastodon/.rbenv/versions/2.5.0/lib/ruby/2.5.0/net/smtp.rb:539:in `open'
May 03 11:15:21 tootcat2 bundle[5368]: /home/mastodon/.rbenv/versions/2.5.0/lib/ruby/2.5.0/net/smtp.rb:539:in `tcp_socket'
May 03 11:15:21 tootcat2 bundle[5368]: /home/mastodon/.rbenv/versions/2.5.0/lib/ruby/2.5.0/net/smtp.rb:549:in `block in do_start'
May 03 11:15:21 tootcat2 bundle[5368]: /home/mastodon/.rbenv/versions/2.5.0/lib/ruby/2.5.0/net/smtp.rb:548:in `do_start'
May 03 11:15:21 tootcat2 bundle[5368]: /home/mastodon/.rbenv/versions/2.5.0/lib/ruby/2.5.0/net/smtp.rb:518:in `start'
May 03 11:15:21 tootcat2 bundle[5368]: /home/mastodon/live/vendor/bundle/ruby/2.5.0/gems/mail-2.7.0/lib/mail/network/delivery_methods/smtp.rb:109:in `start_smtp_session'
May 03 11:15:21 tootcat2 bundle[5368]: /home/mastodon/live/vendor/bundle/ruby/2.5.0/gems/mail-2.7.0/lib/mail/network/delivery_methods/smtp.rb:100:in `deliver!'
May 03 11:15:21 tootcat2 bundle[5368]: 2018-05-03T11:15:21.238Z 5368 TID-orv43zy6g WARN: /home/mastodon/.rbenv/versions/2.5.0/lib/ruby/2.5.0/net/smtp.rb:539:in `initialize'
May 03 11:15:21 tootcat2 bundle[5368]: /home/mastodon/.rbenv/versions/2.5.0/lib/ruby/2.5.0/net/smtp.rb:539:in `open'
May 03 11:15:21 tootcat2 bundle[5368]: /home/mastodon/.rbenv/versions/2.5.0/lib/ruby/2.5.0/net/smtp.rb:539:in `tcp_socket'
May 03 11:15:21 tootcat2 bundle[5368]: /home/mastodon/.rbenv/versions/2.5.0/lib/ruby/2.5.0/net/smtp.rb:549:in `block in do_start'
May 03 11:15:21 tootcat2 bundle[5368]: /home/mastodon/.rbenv/versions/2.5.0/lib/ruby/2.5.0/net/smtp.rb:548:in `do_start'
May 03 11:15:21 tootcat2 bundle[5368]: /home/mastodon/.rbenv/versions/2.5.0/lib/ruby/2.5.0/net/smtp.rb:518:in `start'
May 03 11:15:21 tootcat2 bundle[5368]: /home/mastodon/live/vendor/bundle/ruby/2.5.0/gems/mail-2.7.0/lib/mail/network/delivery_methods/smtp.rb:109:in `start_smtp_session'
May 03 11:15:21 tootcat2 bundle[5368]: /home/mastodon/live/vendor/bundle/ruby/2.5.0/gems/mail-2.7.0/lib/mail/network/delivery_methods/smtp.rb:100:in `deliver!'

...with several prior instances of very similar sequences.