{"id":39972,"name":null,"username":"mchilson","avatar_template":"/user_avatar/support.jodohost.com/mchilson/{size}/70_2.png","created_at":"2006-09-01T13:31:34.000Z","cooked":"\u003cp\u003eCan you guys check into this? All the notification emails to comcast users are bouncing with the following error…\u003c/p\u003e\n\u003cp\u003eConnected to 206.18.177.26 but sender was rejected.\u003cbr\u003e\nRemote host said: 521-EHLO/HELO from sender 204.14.106.10 does not map to mail2.m****here.biz in DNS 521-sending machine name must be provided as a fully 521-qualified domain via EHLO/HELO command.\u003cbr\u003e\n521-see section 4.1.1.1 and 4.1.4 of RFC 2821\u003cbr\u003e\n521 521: Comcast requires that all mail servers must have a PTR record with a valid Reverse DNS entry. Currently your mailserver does not fill that requirement. For more information, refer to:  \u003ca href=\"http://www.comcast.net/help/faq/index.jsp?faq=Email118405\" class=\"inline-onebox\" rel=\"noopener nofollow ugc\"\u003eDiscovery Hub - News \u0026amp; Technology\u003c/a\u003e\u003c/p\u003e\n\u003cp\u003eLooks like something is going on with the reverse DNS lookup.\u003c/p\u003e\n\u003cp\u003eMany thanks!\u003cbr\u003e\nMike\u003c/p\u003e","post_number":1,"post_type":1,"posts_count":3,"updated_at":"2026-08-03T05:51:20.351Z","reply_count":0,"reply_to_post_number":null,"quote_count":0,"incoming_link_count":0,"reads":0,"readers_count":0,"score":0.0,"yours":false,"topic_id":7269,"topic_slug":"trouble-with-comcast-again","display_username":null,"primary_group_name":null,"flair_name":null,"flair_url":null,"flair_bg_color":null,"flair_color":null,"flair_group_id":null,"badges_granted":[],"version":1,"can_edit":false,"can_delete":false,"can_recover":false,"can_see_hidden_post":false,"can_wiki":false,"user_title":"","bookmarked":false,"raw":"Can you guys check into this? All the notification emails to comcast users are bouncing with the following error...\r\n\r\nConnected to 206.18.177.26 but sender was rejected.\r\nRemote host said: 521-EHLO/HELO from sender 204.14.106.10 does not map to mail2.m****here.biz in DNS 521-sending machine name must be provided as a fully 521-qualified domain via EHLO/HELO command.\r\n521-see section 4.1.1.1 and 4.1.4 of RFC 2821\r\n521 521: Comcast requires that all mail servers must have a PTR record with a valid Reverse DNS entry. Currently your mailserver does not fill that requirement. For more information, refer to:  http://www.comcast.net/help/faq/index.jsp?faq=Email118405 \r\n\r\nLooks like something is going on with the reverse DNS lookup.\r\n\r\nMany thanks!\r\nMike","actions_summary":[],"moderator":false,"admin":false,"staff":false,"user_id":793,"hidden":false,"trust_level":1,"deleted_at":null,"user_deleted":false,"edit_reason":null,"can_view_edit_history":true,"wiki":false,"post_url":"/t/trouble-with-comcast-again/7269/1","reactions":[],"current_user_reaction":null,"reaction_users_count":0,"current_user_used_main_reaction":false,"can_accept_answer":false,"can_unaccept_answer":false,"accepted_answer":false,"topic_accepted_answer":null,"can_vote":false}