Chapter 2. General Updates

Since Red Hat Enterprise Linux 7.3, the default value of the first_valid_uid configuration option of Dovecot changed from 500 in Red Hat Enterprise Linux 6 to 1000 in Red Hat Enterprise Linux 7. Consequently, if a Red Hat Enterprise Linux 6 installation did not have first_valid_uid explicitly defined, the Dovecot configuration did not allow users with UID less than 1000 to log in after the update to Red Hat Enterprise Linux 7. Note that only installations where first_valid_uid was not explicitly defined were affected. This problem has been addressed by the post-upgrade script, which now changes the first_valid_uid value from 1000 to the original value on the source system. As a result, users with any UID are able to log in after the update to Red Hat Enterprise Linux 7. (BZ#1388967)