Email not delivered when used in a form, test-mail does work and email log has no errors!

[mmmint]

Hello,

Though sending of test emails do work flawlessly: bin/plugin email test-email -t info@company.com, the rest of the plugin somehow doesn't (for me).

Here my user/config/plugins/email.yaml (for the purpose of anonymity I replaced my own domain.ch with company.com)

enabled: true
from: contact@company.com
to: info@company.com
mailer:
  engine: smtp
  smtp:
    server: mail.cyon.ch
    port: 465
    encryption: ssl
    user: contact@company.com
    password: mypassword
  sendmail:
    bin: '/usr/sbin/sendmail -bs'
content_type: text/html
debug: true

And here the email log content logs/email.log:

[2018-07-31 16:44:44] email.DEBUG: ++ Starting Swift_SmtpTransport << 220 mail.cyon.ch ESMTP ready  >> EHLO test.company.com  << 250-mail.cyon.ch 250-SIZE 52428800 250-8BITMIME 250-PIPELINING 250-HELP 250 AUTH LOGIN  >> AUTH LOGIN  << 334 VXNlcm8hbWU1  >> Y29udGFjdEBhbHAoYWRpYWdub3N0aXNzLmNo  << 334 UGFxc3dvcmQ3  >> Li5hbHByYV9DT04UQUNUJTIwMA==  << 235 2.0.0 OK  ++ Swift_SmtpTransport started [] []
[2018-07-31 16:45:13] email.DEBUG: ++ Starting Swift_SmtpTransport << 220 mail.cyon.ch ESMTP ready  >> EHLO test.company.com  << 250-mail.cyon.ch 250-SIZE 52428800 250-8BITMIME 250-PIPELINING 250-HELP 250 AUTH LOGIN  >> AUTH LOGIN  << 334 VXNlcm8hbWU1  >> Y29udGFjdEBhbHAoYWRpYWdub3N0aXNzLmNo  << 334 UGFxc3dvcmQ3  >> Li5hbHByYV9DT04UQUNUJTIwMA==  << 235 2.0.0 OK  ++ Swift_SmtpTransport started [] []
[2018-07-31 16:45:24] email.DEBUG: ++ Starting Swift_SmtpTransport << 220 mail.cyon.ch ESMTP ready  >> EHLO test.company.com  << 250-mail.cyon.ch 250-SIZE 52428800 250-8BITMIME 250-PIPELINING 250-HELP 250 AUTH LOGIN  >> AUTH LOGIN  << 334 VXNlcm8hbWU1  >> Y29udGFjdEBhbHAoYWRpYWdub3N0aXNzLmNo  << 334 UGFxc3dvcmQ3  >> Li5hbHByYV9DT04UQUNUJTIwMA==  << 235 2.0.0 OK  ++ Swift_SmtpTransport started [] []

Each sending process somehow ends with Swift_SmtpTransport started [] []??

Does somebody know how to make it work?

Thanks!