Two Office 365 accounts rejecting internal messages

%3CLINGO-SUB%20id%3D%22lingo-sub-1917402%22%20slang%3D%22en-US%22%3ETwo%20Office%20365%20accounts%20rejecting%20internal%20messages%3C%2FLINGO-SUB%3E%3CLINGO-BODY%20id%3D%22lingo-body-1917402%22%20slang%3D%22en-US%22%3E%3CP%3EOur%20school%20Office%20365%20domain%20has%20about%2035%20users.%3C%2FP%3E%3CP%3E%26nbsp%3B%3C%2FP%3E%3CP%3EWe%20have%20just%20discovered%20that%202%20users%20are%20bouncing%20internal%20emails.%26nbsp%3B%20If%20anyone%20tries%20to%20send%20an%20email%20to%20either%20of%20the%20users%20they%20get%3A%3C%2FP%3E%3CP%3E%26nbsp%3B%3C%2FP%3E%3CP%3EDelivery%20has%20failed%20to%20these%20recipients%20or%20groups%3A%3C%2FP%3E%3CP%3Exx%20(xx%40staugustines.dorset.sch.uk)%3CBR%20%2F%3EYour%20message%20wasn't%20delivered%20because%20the%20recipient's%20email%20provider%20rejected%20it.%3C%2FP%3E%3CP%3E%3CBR%20%2F%3EDiagnostic%20information%20for%20administrators%3A%3C%2FP%3E%3CP%3EGenerating%20server%3A%20AS8PR01MB7606.eurprd01.prod.exchangelabs.com%3CBR%20%2F%3Exx%40staugustines.dorset.sch.uk%3CBR%20%2F%3ERemote%20Server%20returned%20'550%205.7.520%20Access%20denied%2C%20Your%20organization%20does%20not%20allow%20external%20forwarding.%20Please%20contact%20your%20administrator%20for%20further%20assistance.%20AS(7555)'%3C%2FP%3E%3CP%3E%26nbsp%3B%3C%2FP%3E%3CP%3EI%20have%20checked%20both%20of%20the%20users%20accounts%20and%20neither%20have%20any%20mail%20forwarding%20set.%26nbsp%3B%20And%20it%20is%20only%20affecting%20these%202%20users.%3C%2FP%3E%3CP%3E%26nbsp%3B%3C%2FP%3E%3CP%3EDoes%20anyone%20know%20what%20might%20be%20going%20on%3F%3C%2FP%3E%3CP%3E%26nbsp%3B%3C%2FP%3E%3CP%3EAndy%3C%2FP%3E%3C%2FLINGO-BODY%3E%3CLINGO-LABS%20id%3D%22lingo-labs-1917402%22%20slang%3D%22en-US%22%3E%3CLINGO-LABEL%3EExchange%3C%2FLINGO-LABEL%3E%3C%2FLINGO-LABS%3E%3CLINGO-SUB%20id%3D%22lingo-sub-1920874%22%20slang%3D%22en-US%22%3ERe%3A%20Two%20Office%20365%20accounts%20rejecting%20internal%20messages%3C%2FLINGO-SUB%3E%3CLINGO-BODY%20id%3D%22lingo-body-1920874%22%20slang%3D%22en-US%22%3EHi%2C%20this%20is%20most%20likely%20related%20to%20a%20new%20default%20setting%20in%20the%20outbound%20spam%20filter%20policy.%20It%20was%20recently%20announced%20via%20Message%20center.%20Go%20here%20for%20configuration%20%3CA%20href%3D%22https%3A%2F%2Fprotection.office.com%2Fantispam%22%20target%3D%22_blank%22%20rel%3D%22noopener%20noreferrer%22%3Ehttps%3A%2F%2Fprotection.office.com%2Fantispam%3C%2FA%3E%3CBR%20%2F%3E%3CBR%20%2F%3EFor%20more%20info%3CBR%20%2F%3E%3CA%20href%3D%22https%3A%2F%2Fdocs.microsoft.com%2Fen-us%2Fmicrosoft-365%2Fsecurity%2Foffice-365-security%2Fexternal-email-forwarding%3Fview%3Do365-worldwide%22%20target%3D%22_blank%22%20rel%3D%22noopener%20noreferrer%22%3Ehttps%3A%2F%2Fdocs.microsoft.com%2Fen-us%2Fmicrosoft-365%2Fsecurity%2Foffice-365-security%2Fexternal-email-forwarding%3Fview%3Do365-worldwide%3C%2FA%3E%3C%2FLINGO-BODY%3E
Occasional Visitor

Our school Office 365 domain has about 35 users.

 

We have just discovered that 2 users are bouncing internal emails.  If anyone tries to send an email to either of the users they get:

 

Delivery has failed to these recipients or groups:

xx (xx@staugustines.dorset.sch.uk)
Your message wasn't delivered because the recipient's email provider rejected it.


Diagnostic information for administrators:

Generating server: AS8PR01MB7606.eurprd01.prod.exchangelabs.com
xx@staugustines.dorset.sch.uk
Remote Server returned '550 5.7.520 Access denied, Your organization does not allow external forwarding. Please contact your administrator for further assistance. AS(7555)'

 

I have checked both of the users accounts and neither have any mail forwarding set.  And it is only affecting these 2 users.

 

Does anyone know what might be going on?

 

Andy

1 Reply
Hi, this is most likely related to a new default setting in the outbound spam filter policy. It was recently announced via Message center. Go here for configuration https://protection.office.com/antispam

For more info
https://docs.microsoft.com/en-us/microsoft-365/security/office-365-security/external-email-forwardin...