Some E-Mails sent from osTicket to e-mail adresses won't get delievered. There is an NDR comming back sent from Microsoft, containing the following information:
Your message contains invalid characters (bare line feed characters) which the email servers at xy.com don't support.
Reported error: 550 5.6.11 SMTPSEND.BareLinefeedsAreIllegal; message contains bare linefeeds, which cannot be sent via DATA and receiving system does not support BDAT
For more information see Fix email delivery issues for error code 5.6.11 in Office 365
Is there any setting or fix available? It's critical for our business because customers aren't happy when they don't receive our mails.