{"id":3493,"date":"2025-02-06T13:39:56","date_gmt":"2025-02-06T18:39:56","guid":{"rendered":"https:\/\/easy-admin.ca\/?p=3493"},"modified":"2025-09-08T11:20:13","modified_gmt":"2025-09-08T15:20:13","slug":"postfix-cannot-send-or-receive-email-from-google-gmail","status":"publish","type":"post","link":"https:\/\/easy-admin.ca\/index.php\/2025\/02\/06\/postfix-cannot-send-or-receive-email-from-google-gmail\/","title":{"rendered":"Postfix cannot send or receive email from Google (GMail)"},"content":{"rendered":"\n

Today, I was troubleshooting a CentOS server for a customer experiencing issues with their Postfix mail server. The problem was that Gmail’s mail server was refusing the connection. After verifying that the Postfix configuration was correct, I was still unable to relay emails to Gmail. Upon further investigation, I discovered that the server was using CSF<\/em><\/strong> (ConfigServer Security & Firewall), which could be affecting the connection.<\/p>\n\n\n\n

Here is a temporary fix…<\/p>\n\n\n\n

In CSF make sure that those option a correctly setup<\/strong><\/p>\n\n\n\n

Allow gmail server IP in your ConfigServer Security & Firewall Allow List<\/p>\n\n\n\n

As per today February 6th 2025, here is the official CIDR\/IP list<\/strong><\/p>\n\n\n\n

64.233.160.0\/19 # Google Gmail
66.102.0.0\/20 # Google Gmail
66.249.80.0\/20 # Google Gmail
72.14.192.0\/18 # Google Gmail
74.125.0.0\/16 # Google Gmail
108.177.8.0\/21 # Google Gmail
108.177.96.0\/19 # Google Gmail
172.217.0.0\/19 # Google Gmail
173.194.0.0\/16 # Google Gmail
207.126.144.0\/20 # Google Gmail
209.85.128.0\/17 # Google Gmail
216.58.192.0\/19 # Google Gmail
216.239.32.0\/19 # Google Gmail
108.177.16.0\/24 # Google Gmail
108.177.17.0\/24 # Google Gmail
142.250.220.0\/24 # Google Gmail
142.250.221.0\/24 # Google Gmail<\/p>\n\n\n\n

Allow those IP and restart ConfigServer Security & Firewall<\/strong><\/p>\n\n\n\n

You should now be able to send and receive emails from a Gmail account. However, this is only a temporary solution until I resolve the IPv6 issue in ConfigServer Security & Firewall. If IPv6 is enabled, Gmail will prioritize it for email delivery. Make sure to open the necessary IPv6 ports used for sending and receiving emails to ensure proper functionality.<\/p>\n\n\n\n

Ex.: TCP6_IN = 993,995 TCP6_OUT = 993,995<\/p>\n","protected":false},"excerpt":{"rendered":"

Today, I was troubleshooting a CentOS server for a customer experiencing issues with their Postfix mail server. The problem was that Gmail’s mail server was refusing the connection. After verifying that the Postfix configuration was correct, I was still unable to relay emails to Gmail. Upon further investigation, I discovered that the server was using … Continue reading Postfix cannot send or receive email from Google (GMail)<\/span><\/a><\/p>\n","protected":false},"author":2,"featured_media":3592,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[1],"tags":[],"class_list":["post-3493","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-general"],"_links":{"self":[{"href":"https:\/\/easy-admin.ca\/index.php\/wp-json\/wp\/v2\/posts\/3493","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/easy-admin.ca\/index.php\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/easy-admin.ca\/index.php\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/easy-admin.ca\/index.php\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/easy-admin.ca\/index.php\/wp-json\/wp\/v2\/comments?post=3493"}],"version-history":[{"count":0,"href":"https:\/\/easy-admin.ca\/index.php\/wp-json\/wp\/v2\/posts\/3493\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/easy-admin.ca\/index.php\/wp-json\/wp\/v2\/media\/3592"}],"wp:attachment":[{"href":"https:\/\/easy-admin.ca\/index.php\/wp-json\/wp\/v2\/media?parent=3493"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/easy-admin.ca\/index.php\/wp-json\/wp\/v2\/categories?post=3493"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/easy-admin.ca\/index.php\/wp-json\/wp\/v2\/tags?post=3493"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}