Previously, our delivery of external mail was also instant. i.e. if I sent an email to personal gmail from outlook 2003 client, I would receive it almost instantly in my Gmail.
For the last week or so we have had complaints from users that emails are taking much much longer than usual. In fact some emails are taking out to 45 mins to send!. When I click on an offending email in the queue, it states it READY, and no last errors reports.
There isn't anything in the event log to suggest an issue, other than MAPI errors & cerificate error, which I don not think is relevant
An internal transport certificate expired. Thumbprint:24B30D2970E494F883C2FD99DC16C05D71FCF1C6
Mapi session "/o=Domain/ou=first administrative group/cn=Recipients/cn=billy" exceeded half of the maximum of 16 objects of type "session".
Mapi session "/o=domain/ou=first administrative group/cn=Recipients/cn=John" exceeded half of the maximum of 16 objects of type "session".
I'm almost certain Backpressure is switched off, otherwise I would be seeing these error in the event log
what can I do to identify this sudden issue? We are running exchange 2007 sp3
i cannot identify the cause of why these emails are sitting in the queue , and no errors