Mail Delivery Delay

We have at least one company (and probably more) that when they send us emails it is majorally delayed Anywhere from 2-5 days. I’ve checked everything I can think of. Have these settings in the ini file: SMTPNonStandardMIMETermination=1SMTPNonStandardLineTermination=1

These helped when we weren’t receiving emails from other clients at all.

Any suggestions???

Thanks

Dianna