Check the full email headers for one or more of the delayed emails. If you need help reading them you can post them as a reply to this thread. They will tell the story of when and where the email traveled, and where the delay was if any. Another possibility is that there are different timezones or time offsets being used by some of the servers (-0000 vs -0500 for example) and the email program you are using to read the email is confused. It's also possible that the sending computer or your computer has the timezone set incorrectly causing some confusion. With the full email headers we'll be able to see exactly what is going on with the email.