One very strange issue. ActiveSync devices cannot send e-mail. The are getting error “message was rejected by the server” on Iphone or just “unsuccessful” on Android . Account can be created, messages are received but cannot be viewed.
Test-activesyncconnectivity aswell as remoteconnectovity analyser are showing no errors. Application logs are also clean.
After some Hours of troubleshooting finally we stumbled upon one error on the backend in IIS backend logs:
2016-07-15 07:38:00 ::1 POST /Microsoft-Server-ActiveSync/Proxy/default.eas Cmd=Ping&User=username&DeviceId=androidc2027050747&DeviceType=Android&Log=PrxFrom:%3a%3a1_V141_HH:mail.domain.de_SmtpAdrs:xxxxxxxxxxxx%xxxx-xxxxxxxxxx.de_Fc4_Fid:4_ProvSyncTypeN_Fid:7_ProvSyncTypeN_Fid:8_ProvSyncTypeN_Fid:11_ProvSyncTypeN_Hb1080_Hang0_Fet858_S1_Error:NMStolen_Mbx:serverexchange.domain.local_Throttle0_SBkOffD:BBkOff%3aL%2f-469%2c+ABBkOff%3aL%2f-480%2c+EffBkOff%3aL%2f-469_SyncHC-
It turns out that the issue is caused byt the wildcard ‘*’ character in the beginning of the default accepted Domian.
After removing the * and restart of transport and frontedn transport the issue got resolved. You will have to assign temporally some other accepted Domain as default and change the e-mail policy to be able to edit the one with the *.
The same issue appears if the default accepted domain and the UPN of the user in AD do not mach.
Update: The same error message appears if the uploadReadAheadSize is smaller then the attachement.
“Default Web Site/Microsoft-Server-ActiveSync” -section:system.webServer/serverRuntime /uploadReadAheadSize:”52428800″