Retrievers

• fetchmail
• getmail4

Filters

• procmail - mda
• imapfilter
• yample
• mailfilter - mda?
• maildrop - mda

Syncers

• imapcopy
• imapsync
• isync
• mailsync
• offlineimap

Converters

• mailutils
• mb2md

Proxyies

• imapproxy
• perdition