BM 37 lastest sp

I have a filter exception to allow a pool of 4096 external servers i.e.

Example network range as follows


smtp port 25 stateful filter

This is used to allow upstream email servers access to our GroupWise GWIA

At any one time only 8 servers in the above range are actually active

Using the above filter exception the upstream servers are unable to
connect to our GWIA

The 8 servers can be resolved via a DNS lookup

If I specifically allow each of the 8 servers a filter exception they
connect OK


Is the range to large

Is BM37 unable to perform this task

Or could it be caused by hardware performance

Thanks in advance