Update: Gmail not blacklisted anymore.
< OK: Host www.gmail.com clean.
> WARN: http://www.spamhaus.org/query/bl?ip=22.214.171.124
> WARN: Host www.gmail.com blacklisted.
$ host gmail.com
gmail.com has address 126.96.36.199
gmail.com has address 188.8.131.52
gmail.com has address 184.108.40.206
gmail.com has address 220.127.116.11
Querying Spamhaus, we find:
18.104.22.168 is listed in the SBL, in the following records:
22.214.171.124 is listed in the SBL, in the following records:
126.96.36.199 is listed in the SBL, in the following records:
188.8.131.52 is listed in the SBL, in the following records:
Here is the probable reason they were blocked:
Spam Operation: Canadian Pharmacy
184.108.40.206/24 is listed on the SBL as being assigned to, being under the control of, or being otherwise connected with a known spam operation listed on the ROKSO database as: Canadian Pharmacy
Looking for more details, it seems that spammers were using docs.google.com to post some documents, which are stored in the same /24 as gmail. Spamhaus decided to blacklist the whole subnet. Details:
Address: 220.127.116.11 – 18.104.22.168
Please stop supporting spammers.
You can start by removing the following.
Check out Sucuri Security for a professional blacklist, Whois and malware monitoring solution.