Questions to sendmail with wordpress

Hello, I have the 10$ Wordpress droplet. I had to reinstall sendmail and I cannot make it work again.

Problem: registration/pwd change/whatever that sends mail in WP hangs. Emails are delivered but the website hangs which makes users click the send button 10 million times.

Done so far:

• followed the tutorial on DO to set up sendmail
• got fully qualified domain name “droplet.example.com”
• set up the FQDN in /etc/hosts and /etc/hostname and as droplet name
• made A records for that FQDN
• made lines for internal and external IPs in /etc/hosts
• set up masquerading in sendmail.mc
• removed all lines featuring 127.0.0.1 in sendmail.mc and making sure they are removed from sendmail.cf too

After each change I restarted the sendmail service of course.

No effects so far.

My questions:

• how come emails sent through wordpress are not logged in /var/log/mail.log ? Where does WP keep mail logs?
• how come emails sent through wordpress are not in $ mailq even though they obviously hang at least 5 minutes?
• did I forget something with that sendmail configuration?