ERROR: Connection dropped by IMAP server.
Common error while accessing email account via squirrel mail client on cPanel server. This error occurs due to wrong ownership of file or folder located under etc or mail directory. Here is what worked for me on cPanel server. Suppose cPanel username is xyz to fix the issue execute following commands on server.
[root@server ]#cd /home/xyz
[root@server ]#chown xyz.xyz mail -R
[root@server ]#chown xyz.mail etc -R
lowest numbered MX record points to local host
Generally you will get error lowest numbered MX record points to local host if entry for that domain doesn’t exists under /etc/localdomains or hostname is missing from localdomain simply adding it in localdomain will fix the issue. In case, if domains MX record is pointing to remote mail server then remove domain from localdomain and add it in /etc/remotedomains.
Below is command to find out ports which are in use using netstat & cut.
netstat -na | grep 'tcp\|udp' | awk '{print $4}' | cut -d: -f2 | sort | uniq -c | awk '{print $2}'
Below is description of each commands :: Netstat command is used to check all incoming and outgoing connections on linux server. Using Grep command you can sort lines which are matching pattern you defined. AWk is very important command generally used for scanning pattern and process it. It is powerful tool for shell scripting. Sort is used to sort output and sort -n is for sorting output in numeric order. Uniq -c this help to get uniq output by deleting duplicate lines from it.
