[APS]

OK, but it is strange that I often see these long delays on emails coming into my work account, via Messagelabs, from NTL more or less alone and only in recent weeks.

Often the delays are seen when NTL will be busy and the Messagelabs servers quiet (ML being a business service), e.g. evenings.

I would say the problem is therefore more likely in NTLs network or backbone link.

Even if you accept that two servers might not be able to make a connection sometimes the retry algorithm cannot be too clever if it ends up delaying an email transmission by 3.5 days.

APS