Mails from cPanel to MS Office365 - Exchange Online

Operating System & Version
CentOS 7
cPanel & WHM Version
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davorg

Active Member
May 13, 2013
41
4
58
cPanel Access Level
Root Administrator
When sending to some users, which are using Office365 in MS cloud I got delivery error and returned message:

SMTP error from remote mail server after end of data:
554 5.6.211 Invalid MIME Content: Single text value size (32799) exceeded allowed maximum (32768) for the 'X-Matching-Connectors' header. [AM5P194MB0195.EURP194.PROD.OUTLOOK.COM] [AM6PR02CA0017.eurprd02.prod.outlook.com] [VI1EUR05FT026.eop-eur05.prod.protection.outlook.com]
Reporting-MTA: dns;

But sending mail to some other user, which is using same domain on Microsoft is ok. Sending from some other mail system - I have one server with postfix, ... is also ok.

Have anyone similar errors?
 

davorg

Active Member
May 13, 2013
41
4
58
cPanel Access Level
Root Administrator
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