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archiveopteryx
clamsmtp
dkimproxy
dovecot
dspam
exim
listmonk
mailhog
mailman
mlmmj
nullmailer
opensmtpd
petidomo
popa3d
postfix
postgrey
postsrsd
public-inbox
rspamd
spamassassin
spf-engine
sympa
system-sendmail
vsmtp