The best replacement for mtom is swa.

The best alternatives to mtom are rated as following:
★★★★★  swa
★★★★★  dime
★★★★  mime
★★★★  base64
★★★  soap with attachments
★  swaref
  mtow

Your alternative for mtom is not listed? Suggest!
Speaking about mtom, one probably shouldn't forget about basichttpbinding.

Other search terms related to mtom and their ratings are:
★★★★★ basichttpbinding
★★★★ spring ws
★★ axis
You have in mind a companion for mtom and it is not yet here? Propose!



Google Trends

Scale is based on the average worldwide traffic of mtom in all years. Click on graph for more.
mtom
swa
dime