A user reported that she was no longer able to download her email after receiving a new system. She uses Outlook, which was reporting the following error:
Task 'jasmith@example.com - Receiving' reported error (0x800CCC92) :
'Your e-mail server rejected your login. Verify your user name and
password for this account in Account Settings. The server responded:
-ERR [AUTH] Plaintext authentication disallowed on non-secure (SSL/TLS)
connections.'
At first I thought the tech who upgraded the system had made some
change to Outlook on the system, but I eventually realized that the email
server using
dovecot for
POP3 email
access was denying access, because the system had a new IP address. The
user was using POP3, port 110, for downloading email and I had previously
added the old IP address to the login_trusted_networks
line in /etc/dovecot/dovecot.conf file on the email
server. By adding an IP address or IP address range to that line, you can
configure dovecot to allow users to login using an unencrypted userid
and password, i.e., plaintext authentication, from
the specified IP address or range of addresses. The relevant section in
dovecot.conf is shown below:
# Space separated list of trusted network ranges. Connections from these # IPs are allowed to override their IP addresses and ports (for logging and # for authentication checks). disable_plaintext_auth is also ignored for # these networks. Typically you'd specify your IMAP proxy servers here. login_trusted_networks = 192.168.0.0/24 192.168.1.0/24 172.45.55.82
In the case above, the server will accept plaintext passwords from any
system in the 192.168.0.0/24 address range, i.e., 192.168.0.0 to
192.168.0.255, the 192.168.1.0/24 address range, and from the specific
IP address 172.45.55.82, which was the user's IP address. After updating
her IP address in the file, I restarted dovecot with
service dovecot restart.
The system uses sendmail
for sending email and I also had to update /etc/mail/access
to include her IP address, since the change to the dovecot configuration file
allowed her to download her email, but sendmail would still not except any
email sent from her computer, since relaying was permitted from her old
email address, but not her new one. I added her IP address and a comment
line to the /etc/mail/access file.
# J. A. Smith 172.45.55.82 RELAY
I then used makemap hash
to generate an updated /etc/mail/access.db file.
# makemap hash /etc/mail/access </etc/mail/access
She was then able to send as well as receive email; I didn't need to restart sendmail.
