Newsletter shipping does not work

Summary

The newsletter shipping is already hanging when sending the 1st Mail. Same behavior is also with the test region.

Steps to reproduce

  • Login as Orga member
  • In top menu "Administration" > "E-Mail-Verteiler"

What is the current bug behavior?

(What actually happens)

What is the expected correct behavior?

The newsletter should send all mails.

Relevant error messages and/or screenshots

newsletter01

Newsletter_Screenshot

Slack discussion:
https://yunity.slack.com/archives/C1T1ZM9A4/p1571134581140800?thread_ts=1571134581.140800
https://yunity.slack.com/archives/C1T1ZM9A4/p1574699785322200

https://sentry.io/organizations/foodsharing-ev/issues/1290351839/?project=1400912

Possible fixes

(If you can, link to the line of code that might be responsible for the problem)

Edited by Johannes