I have ALM22.
imapd service is running under cyrus:mail account.
/var/run/saslauthd is owned by root:root.
So imapd cannot connect to saslauthd.
Possible solutions:
1) chgrp mail /var/run/saslauthd (in %files of sasl2)
2) groupadd saslauthd
   chgrp saslauthd /var/run/saslauthd
   user2group cyrus saslauthd
   ...in %trigger of sasl2 for imap

Steps to Reproduce:
1. apt-get install cyrus-{imapd,imapd-utils,sasl2}
2. /etc/imapd.conf: sasl_pwcheck_method: saslauthd; sasl_mech_list: plain
3. service cyrus-imapd start; service saslauthd start
4. cyradm -u cyrus
Actual Results:  
imapd wrotes to /tty/dev12: cannot connect with saslautd: permission denied

Expected Results:  
nothing:-)