emails not sent

[Docmale]

Describe the bug
When I fill out and submit an application I get the message 'Email konnte nicht an...'. However, the application appears in the list of received applications. Neither the contact nor the applicant receives an email.

To Reproduce
Steps to reproduce the behavior:
1.See the last applicatins in Augsburg

[f1sh1918]

Here are the server logs. Its happening on staging
https://staging.bayern.ehrenamtskarte.app/beantragen

Jul 03 09:25:39 entitlementcard-test.tuerantuer.org backend[1446911]: [JettyServerThreadPool-21] ERROR app.ehrenamtskarte.backend.mail.Mailer - Failed to send email [Subject: 'Antrag erfolgreich eingereicht'], reason: Third party error
Jul 03 09:25:39 entitlementcard-test.tuerantuer.org backend[1446911]: [JettyServerThreadPool-21] ERROR app.ehrenamtskarte.backend.common.webservice.GraphQLExceptionHandler - Exception while fetching data (/result) : null

[f1sh1918]

fixed by https://git.tuerantuer.org/DF/salt/pulls/170