4.7.1 smtp Greylistet in 5 min please try again later – Exchange 2003 SP2
Greylisting is an anti-spam measure.
When a new server connects for the first time, the greylisting server sends a SMTP protocol message that says: “Graylistet in 5 min please try again later”.
The wait time can be different, but usually 5 min.
The problem is exchange 2003 (with SP2) by deafult only waits for 1 min.
That has to be changed.
HKLM\System\CurrentControlSet\Services\SMTPSvc
Create a new DWORD value GlitchRetrySeconds
Change the Base to Decimal
Set 360 for 6 min.
Restart the SMTP service.
