{"id":220,"date":"2010-05-13T22:23:39","date_gmt":"2010-05-13T21:23:39","guid":{"rendered":"http:\/\/www.penguino.co.uk\/?p=220"},"modified":"2011-06-14T18:30:39","modified_gmt":"2011-06-14T17:30:39","slug":"o2-broadband-cannot-sent-outbound-email-to-external-smtp-server-via-port-25","status":"publish","type":"post","link":"http:\/\/www.penguino.co.uk\/computing\/o2-broadband-cannot-sent-outbound-email-to-external-smtp-server-via-port-25","title":{"rendered":"O2 broadband &#8211; cannot sent outbound email to external SMTP server via port 25"},"content":{"rendered":"\n<!-- SEO Ultimate (http:\/\/www.seodesignsolutions.com\/wordpress-seo\/) - Code Inserter module -->\n<!-- SEO Ultimate before item content-->\r\n<!-- #SEO Ultimate before item content-->\n<!-- \/SEO Ultimate -->\n\n<p>I was helping a friend who has recently installed O2 (UK) broadband at his premises.<\/p>\n<p><img decoding=\"async\" loading=\"lazy\" class=\"size-thumbnail wp-image-222 alignright\" style=\"border: 0px;\" title=\"4204-org\" src=\"http:\/\/www.penguino.co.uk\/wp-content\/uploads\/2010\/05\/4204-org-150x150.jpg\" alt=\"O2 logo\" width=\"150\" height=\"150\" \/><\/p>\n<p>He was using Microsoft Outlook and the first thing he noticed was that &#8211; he was unable to send\/relay emails via his own SMTP server setting, although his incoming emails were unaffected.<\/p>\n<p>My initial diagnostic on his PC, was to check his\u00a0outgoing port 25 access to various external smtp servers, as expected, I was unable to connect to any.<\/p>\n<p>I went through his PC&#8217;s firewall settings, antivirus and spam filter settings, and even I investigated\u00a0the router&#8217;s firewall configuration.<\/p>\n<p>After almost an hour,\u00a0I could not find the reason why\u00a0the outgoing smtp connections were denied &#8211; until&#8230;.. thanks to David Nicoll&#8217;s blog, I&#8217;ve found the answer.<\/p>\n<p>[Link is now dead but read on\u00a0<del>http:\/\/blog.davenicoll.com\/2008\/10\/29\/cant-send-email-on-o2-broadband\/]<\/del><\/p>\n<p>In essence: <strong>O2 broadband\u00a0blocks all outgoing port 25 SMTP connection<\/strong> UNLESS you are using O2&#8217;s own mailserver, and relaying mail through their server.<\/p>\n<p>Luckily for my friend, he is using Spam Arrest&#8217;s SMTP server &#8211; which allows connection from an alternative port and thus by-passed O2&#8217;s restriction<\/p>\n<p><a href=\"http:\/\/www.spamarrest.com\/support\/client\/\">http:\/\/www.spamarrest.com\/support\/client\/<\/a><\/p>\n<p>(I am not trying to advertise for Spam Arrest &#8211; just please note that you do need to be a paid user to use spam arrest&#8217;s smtp server for sending\u00a0outgoing mail)<\/p>\n<p>I hope this will help some new O2 broadband users looking for a solution.<\/p>\n<p><script type=\"text\/javascript\">\/\/ <![CDATA[\ngoogle_ad_client = \"pub-4049676200689259\";\n\/* ArticleInLine *\/\ngoogle_ad_slot = \"6924442896\";\ngoogle_ad_width = 468;\ngoogle_ad_height = 60;\n\/\/ ]]><\/script><br \/>\n<script src=\"http:\/\/pagead2.googlesyndication.com\/pagead\/show_ads.js\" type=\"text\/javascript\">\n<\/script><\/p>\n\n<!-- SEO Ultimate (http:\/\/www.seodesignsolutions.com\/wordpress-seo\/) - Code Inserter module -->\n<!-- SEO Ultimate after item content-->\r\n<!-- #SEO Ultimate after item content-->\n<!-- \/SEO Ultimate -->\n\n","protected":false},"excerpt":{"rendered":"<p>I was helping a friend who has recently installed O2 (UK) broadband at his premises. He was using Microsoft Outlook and the first thing he noticed was that &#8211; he was unable to send\/relay emails via his own SMTP server setting, although his incoming emails were unaffected. My initial diagnostic on his PC, was to [&hellip;]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_s2mail":"","ngg_post_thumbnail":0},"categories":[3,270],"tags":[22,63,64,65,66],"_links":{"self":[{"href":"http:\/\/www.penguino.co.uk\/wp-json\/wp\/v2\/posts\/220"}],"collection":[{"href":"http:\/\/www.penguino.co.uk\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"http:\/\/www.penguino.co.uk\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"http:\/\/www.penguino.co.uk\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"http:\/\/www.penguino.co.uk\/wp-json\/wp\/v2\/comments?post=220"}],"version-history":[{"count":0,"href":"http:\/\/www.penguino.co.uk\/wp-json\/wp\/v2\/posts\/220\/revisions"}],"wp:attachment":[{"href":"http:\/\/www.penguino.co.uk\/wp-json\/wp\/v2\/media?parent=220"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"http:\/\/www.penguino.co.uk\/wp-json\/wp\/v2\/categories?post=220"},{"taxonomy":"post_tag","embeddable":true,"href":"http:\/\/www.penguino.co.uk\/wp-json\/wp\/v2\/tags?post=220"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}