The best replacement for express mail is priority mail.

The best alternatives to express mail are rated as following:
★★★★★  priority mail
★★★  priority
★★  certified mail
★★  registered mail
★  first class mail
★  courier
  first class
  regular mail
  expedited mail
  usps priority
  normal mail
  overnight mail

Your alternative for express mail is not listed? Suggest!
Speaking about express mail, one probably shouldn't forget about delivery confirmation.

Other search terms related to express mail and their ratings are:
★★★★★ delivery confirmation
You have in mind a companion for express mail and it is not yet here? Propose!



Google Trends

Scale is based on the average worldwide traffic of express mail in all years. Click on graph for more.
express mail
priority mail
priority