The best replacement for sieve is strainer.

The best alternatives to sieve are rated as following:
★★★★★  strainer
★★★★  colander
★★  sifter
★★  food mill
★★  procmail
★  mesh
★  sift
★  maildrop
★  silica gel
  strainerhow to use a sieve
  cheesecloth
  laser diffraction
  rubble sifter
  activated alumina

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

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



Google Trends

Scale is based on the average worldwide traffic of sieve in all years. Click on graph for more.
sieve
strainer
colander