Another data point. Since I encrypt all email (SSL/TLS) and normally scan with avast! anyway, using Stunnel for the encryption/decryption, compared uploading messages with/without avast!, but still using TLS. Setup is 384kbps DSL uplink, XP with SP2, Thunderbird mail client, Sygate PF. Total message size as received was 5.3MB, including a .kap (map) attachment. With avast!/Stunnel took 176 sec (30KB/sec) to upload; without avast!, using TLS in TB, took 150sec (35KB/sec). Max achievable link would be about 40KB/sec without encryption. So even with encryption, I am not seeing the scanning overhead of the others. Renamed the .kap to an .exe, and it took 195 seconds, including waiting for a warning message from avast that it was a suspicious file extension. Tried again with a real .exe about the right size, actually ran slightly faster (more efficient scanning of known types?). So what does all this mean? Seems like there is nothing inherent in the flow through avast! that causes huge time discrepancies, at least with XP. Results are entirely satisfactory and about as expected. Message takes a lot longer oubound than inbound, but this is normal because the link is assymetric in speed. Unable to repeat other results; do not see an avast! problem in this area. Zone Alarm an issue? (vs Sygate). Use of W98 and issue? Faster uplink an issue? (93kBps or 750kbps is much faster than most). Something else to chew on.