This message was created automatically by mail<\/span><\/a> delivery software.<\/span>\n \nA message that you sent could not be delivered to one or more of its\nrecipients.<\/span> This is a permanent error.<\/span> The following address(<\/span>es)<\/span> failed:<\/span>\n \nemailaddress@<\/span>domain.<\/span>com\n(<\/span>ultimately generated from xxx@<\/span>domain.<\/span>com)<\/span>\nSMTP error from remote mail<\/span><\/a> server after end<\/span><\/a> of data:<\/span>\nhost ASPMX.<\/span>L.<\/span>GOOGLE.<\/span>COM [<\/span>ipv6 address]<\/span>:<\/span>\n550-<\/span>5.<\/span>7.<\/span>1 [<\/span>ipv6 address]<\/span> Our system<\/span><\/a> has detected that this message does\n550<\/span>-<\/span>5.<\/span>7.<\/span>1 not meet IPv6 sending guidelines regarding PTR records and\n550<\/span>-<\/span>5.<\/span>7.<\/span>1 authentication.<\/span> Please review\n550<\/span>-<\/span>5.<\/span>7.<\/span>1\u00a0 https:<\/span>\/\/support.google.com\/mail\/?p=ipv6_authentication_error for more<\/span>\n550<\/span> 5.<\/span>7.<\/span>1 information.<\/span> z10si11396270par.<\/span>118 -<\/span> gsmtp<\/pre><\/div><\/div>\n <\/p>\n
I’m using VPS hosting with VESTACP and it currently doesn’t support IPV6. However, for some strange reason EXIM (the mail transfer agent) is using IPV4 and also IPV6. I checked this by running the command:<\/p>\n
<\/a>Source code<\/a><\/td> <\/a> <\/a> <\/a> <\/td><\/tr><\/table><\/div>lsof -<\/span>Pni |<\/span> grep exim<\/pre><\/div><\/div>\n <\/p>\n<\/a><\/p>\n
What I needed to do was disable IPv6 from EXIM so after some research all I had to do was go into etc\/exim\/exim.conf \u00a0and add the following line:<\/p>\n
<\/a>Source code<\/a><\/td> <\/a> <\/a> <\/a> <\/td><\/tr><\/table><\/div>disable_ipv6 =<\/span> true<\/span><\/pre><\/div><\/div>\n <\/p>\n<\/a><\/p>\n
Save the file and then restart exim by using the following command:<\/p>\n
<\/a>Source code<\/a><\/td> <\/a> <\/a> <\/a> <\/td><\/tr><\/table><\/div>service exim restart<\/pre><\/div><\/div>\n <\/p>\n
Then check to make sure exim is no longer using IPV6 by using the command:<\/p>\n
<\/a>Source code<\/a><\/td> <\/a> <\/a> <\/a> <\/td><\/tr><\/table><\/div>lsof -<\/span>Pni |<\/span> grep exim<\/pre><\/div><\/div>\n<\/a><\/p>\n
You will now see that IPv6 is no longer listed.<\/p>\n
RESOURCES<\/div>List of resources related to this article:<\/p>\nVESTACP<\/a> – Open Source Free Control Panel<\/p>\n
EXIM<\/a> – Information about Exim email mailer<\/p>\n<\/div><\/div>\n
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\n\n\nName<\/label>\n<\/div>\nEmail<\/label>\n<\/div>\n\n<\/div>\n<\/form>\n<\/div>\n<\/p>\r\n\r\n<\/div><\/div>\n<\/div>","protected":false},"excerpt":{"rendered":"Strangely, today an email delivery failed and I decided to investigate further. The email subject was “Mail delivery failed: returning message to sender” The content in the bounced email was:   I’m using VPS hosting with VESTACP and it currently doesn’t support IPV6. However, for some strange reason EXIM (the mail transfer agent) is using […]<\/p>\n","protected":false},"author":1,"featured_media":3880,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[761,1043],"tags":[1967,1934,97,188,1969,1968],"class_list":["post-3878","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-google-technology","category-websites","tag-exim","tag-gmail","tag-google","tag-mail","tag-relay","tag-vestacp"],"_links":{"self":[{"href":"https:\/\/www.businesslegions.com\/blog\/wp-json\/wp\/v2\/posts\/3878","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.businesslegions.com\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.businesslegions.com\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.businesslegions.com\/blog\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.businesslegions.com\/blog\/wp-json\/wp\/v2\/comments?post=3878"}],"version-history":[{"count":7,"href":"https:\/\/www.businesslegions.com\/blog\/wp-json\/wp\/v2\/posts\/3878\/revisions"}],"predecessor-version":[{"id":3889,"href":"https:\/\/www.businesslegions.com\/blog\/wp-json\/wp\/v2\/posts\/3878\/revisions\/3889"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.businesslegions.com\/blog\/wp-json\/wp\/v2\/media\/3880"}],"wp:attachment":[{"href":"https:\/\/www.businesslegions.com\/blog\/wp-json\/wp\/v2\/media?parent=3878"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.businesslegions.com\/blog\/wp-json\/wp\/v2\/categories?post=3878"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.businesslegions.com\/blog\/wp-json\/wp\/v2\/tags?post=3878"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}