A couple of days ago, I stopped being able to download my email from comcast via pop3. Every time I ask Thunderbird to get my mail, it says "Failed to connect to mail.comcast.net". Thing is, I can send mail just fine. So I thought to myself, why not just try to ping the servers. This is what I get:
procyon@MSI-GS60-6QE:~$ ping mail.comcast.net
ping: mail.comcast.net: Name or service not known
procyon@MSI-GS60-6QE:~$ ping smtp.comcast.net
PING smtp.g.comcast.net (96.114.157.81) 56(84) bytes of data.
64 bytes from omta-po.sys.comcast.net (96.114.157.81): icmp_seq=1 ttl=51 time=60.7 ms
64 bytes from omta-po.sys.comcast.net (96.114.157.81): icmp_seq=2 ttl=51 time=69.7 ms
64 bytes from omta-po.sys.comcast.net (96.114.157.81): icmp_seq=3 ttl=51 time=67.2 ms
64 bytes from omta-po.sys.comcast.net (96.114.157.81): icmp_seq=4 ttl=51 time=59.7 ms
However, I happen to dual boot this laptop, so I switched over to Windows 10 to try pinging mail.comcast.net from there. Lo and behold:
C:\Users\Scott>ping mail.comcast.net
Pinging imap.ge.xfinity.com [96.117.3.96] with 32 bytes of data:
Request timed out.
Request timed out.
Request timed out.
Request timed out.
So it's obviously not set up to respond to ping, but the domain DID get resolved (to something else) or so it seems. I don't know how to begin to debug this sort of problem. Does anyone out there have any ideas? Comcast's customer support was useless, as expected. Thank you.
tl;dr: This turned out to be an issue with my /etc/resolv.conf file.
Between LeonidMew's answer and Terrance's comment, I was able to piece this together. My nslookup for mail was the same as LeonidMew's. But when I did what Terrance suggested, and tried nslookup in Windows, the Address was pointing to my router at 192.168.0.1. I knew I had seen 127.0.0.53 before when I was Googling around trying to find an answer, and I realized I had seen it in my resolv.conf file. I edited that file, and changed 127.0.0.53 to 192.169.0.1, and my system was successfully able to find and connect with mail.comcast.net. Thanks very much for all of your help.
Can you reconfigure email client to use imap? Seems imap working fine, with address imap.comcast.net
nslookup for mail:
Change from imap.comcast.net to imap.ge.xfinity.com and it will work. Above post shows issue.