{"id":348,"date":"2025-05-06T07:51:53","date_gmt":"2025-05-06T05:51:53","guid":{"rendered":"https:\/\/www.24x7serverguard.com\/blog\/?p=348"},"modified":"2025-05-06T07:51:53","modified_gmt":"2025-05-06T05:51:53","slug":"when-youre-facing-incoming-email-issues-on-a-cpanel-or-similar-hosting-server-there-are-several-key-areas-you-should-investigate-heres-a-structured-troubleshooting-checklist","status":"publish","type":"post","link":"https:\/\/www.24x7serverguard.com\/blog\/cpanel\/when-youre-facing-incoming-email-issues-on-a-cpanel-or-similar-hosting-server-there-are-several-key-areas-you-should-investigate-heres-a-structured-troubleshooting-checklist\/","title":{"rendered":"When you&#8217;re facing incoming email issues on a cPanel or similar hosting server, there are several key areas you should investigate. Here&#8217;s a structured troubleshooting checklist:"},"content":{"rendered":"\n<h3 class=\"wp-block-heading\">\u2705 1. <strong>DNS and MX Records<\/strong><\/h3>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Check if <strong>MX records<\/strong> point to the correct mail server (e.g., <code>mail.yourdomain.com<\/code>).<\/li>\n\n\n\n<li>Use tools like <a class=\"\" href=\"https:\/\/mxtoolbox.com\">MXToolbox<\/a> to verify DNS propagation and configuration.<\/li>\n\n\n\n<li>Ensure no conflicting <strong>A<\/strong> or <strong>CNAME<\/strong> records for the mail subdomain.<\/li>\n<\/ul>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h3 class=\"wp-block-heading\">\u2705 2. <strong>Mail Server Logs<\/strong><\/h3>\n\n\n\n<p>Check these log files for errors:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li><code>\/var\/log\/exim_mainlog<\/code> \u2192 Main Exim mail delivery log<\/li>\n\n\n\n<li><code>\/var\/log\/exim_rejectlog<\/code> \u2192 Shows rejected emails<\/li>\n\n\n\n<li><code>\/var\/log\/exim_paniclog<\/code> \u2192 For critical Exim errors<\/li>\n<\/ul>\n\n\n\n<p>Use:<\/p>\n\n\n\n<p><mark style=\"background-color:rgba(0, 0, 0, 0)\" class=\"has-inline-color has-luminous-vivid-amber-color\">tail <\/mark>-f \/var\/log\/exim_mainlog<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">\u2705 3. <strong>Firewall and Port Access<\/strong><\/h3>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Confirm <strong>port 25<\/strong> (SMTP), <strong>110\/995<\/strong> (POP3), and <strong>143\/993<\/strong> (IMAP) are open.<\/li>\n\n\n\n<li>Check CSF or any external firewall blocking mail ports.<\/li>\n<\/ul>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h3 class=\"wp-block-heading\">\u2705 4. <strong>Email Account Configuration<\/strong><\/h3>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Check if the email account exists in cPanel.<\/li>\n\n\n\n<li>Ensure mailbox is <strong>not full<\/strong> and the domain is active.<\/li>\n\n\n\n<li>Look for any <strong>email filters<\/strong> or <strong>forwarders<\/strong> that could be affecting delivery.<\/li>\n<\/ul>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h3 class=\"wp-block-heading\">\u2705 5. <strong>Spam or Blacklist Issues<\/strong><\/h3>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Check if your domain\/IP is blacklisted.<\/li>\n\n\n\n<li>Ensure SPF, DKIM, and DMARC records are correctly configured.<\/li>\n<\/ul>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h3 class=\"wp-block-heading\">\u2705 6. <strong>Check Email Routing in cPanel<\/strong><\/h3>\n\n\n\n<ul class=\"wp-block-list\">\n<li>In cPanel \u2192 <strong>Email Routing<\/strong>, ensure it\u2019s set to the correct mode:\n<ul class=\"wp-block-list\">\n<li><strong>Local Mail Exchanger<\/strong> if mail is hosted locally.<\/li>\n\n\n\n<li><strong>Remote Mail Exchanger<\/strong> if using third-party services like Google Workspace.<\/li>\n<\/ul>\n<\/li>\n<\/ul>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h3 class=\"wp-block-heading\">\u2705 7. <strong>Disk Space<\/strong><\/h3>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Ensure the hosting account or server isn&#8217;t out of disk space.<\/li>\n<\/ul>\n\n\n\n<p><mark style=\"background-color:rgba(0, 0, 0, 0)\" class=\"has-inline-color has-luminous-vivid-amber-color\">df <\/mark>-h<\/p>\n\n\n\n<p>======================================================================<\/p>\n\n\n\n<p><\/p>\n\n\n\n<p><\/p>\n\n\n\n<h2 class=\"wp-block-heading\">\u2705 <strong>Incoming Email Issue Checklist \u2013 TechSpark IT Solutions<\/strong><\/h2>\n\n\n\n<h3 class=\"wp-block-heading\">\ud83d\udd39 1. <strong>Check DNS &amp; MX Records<\/strong><\/h3>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Verify MX records point to correct mail server (e.g., <code>mail.domain.com<\/code>)<\/li>\n\n\n\n<li>Confirm MX priority is correct<\/li>\n\n\n\n<li>Use: <code>dig domain.com MX +short<\/code> or online tools like MXToolbox<\/li>\n\n\n\n<li>Ensure A record for mail server exists<\/li>\n<\/ul>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h3 class=\"wp-block-heading\">\ud83d\udd39 2. <strong>Examine Mail Logs (Exim)<\/strong><\/h3>\n\n\n\n<p><mark style=\"background-color:rgba(0, 0, 0, 0)\" class=\"has-inline-color has-luminous-vivid-amber-color\">tail <\/mark>-f \/var\/log\/exim_mainlog<br><mark style=\"background-color:rgba(0, 0, 0, 0)\" class=\"has-inline-color has-luminous-vivid-amber-color\">tail <\/mark>-f \/var\/log\/exim_rejectlog<br><mark style=\"background-color:rgba(0, 0, 0, 0)\" class=\"has-inline-color has-luminous-vivid-amber-color\">tail <\/mark>-f \/var\/log\/exim_paniclog<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Look for reject reasons like &#8220;550&#8221;, &#8220;relay not permitted&#8221;, etc.<\/li>\n<\/ul>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h3 class=\"wp-block-heading\">\ud83d\udd39 3. <strong>Check Firewall &amp; Ports<\/strong><\/h3>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Ensure ports 25, 465, 587 (SMTP), 110\/995 (POP), 143\/993 (IMAP) are open<\/li>\n\n\n\n<li>Check CSF: <code>csf -g &lt;IP><\/code> to see if IP is blocked<\/li>\n\n\n\n<li>Temporarily disable CSF to test: <code>csf -x<\/code><\/li>\n<\/ul>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h3 class=\"wp-block-heading\">\ud83d\udd39 4. <strong>Validate Email Account<\/strong><\/h3>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Confirm email exists under cPanel > Email Accounts<\/li>\n\n\n\n<li>Mailbox quota not exceeded<\/li>\n\n\n\n<li>No custom filters or forwarders blocking mail<\/li>\n<\/ul>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h3 class=\"wp-block-heading\">\ud83d\udd39 5. <strong>Check Email Routing<\/strong><\/h3>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Go to <strong>cPanel > Email Routing<\/strong><\/li>\n\n\n\n<li>Should be \u201cLocal Mail Exchanger\u201d for local hosting<\/li>\n\n\n\n<li>Set to \u201cRemote Mail Exchanger\u201d for Google\/Microsoft mail<\/li>\n<\/ul>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h3 class=\"wp-block-heading\">\ud83d\udd39 6. <strong>Blacklist \/ Spam Configuration<\/strong><\/h3>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Check if your IP\/domain is blacklisted \u2013 use MXToolbox<\/li>\n\n\n\n<li>Verify SPF, DKIM, DMARC:<\/li>\n<\/ul>\n\n\n\n<p>dig +short TXT domain.com<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Ensure emails are not getting flagged by spam filters<\/li>\n<\/ul>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h3 class=\"wp-block-heading\">\ud83d\udd39 7. <strong>Check Disk Usage<\/strong><\/h3>\n\n\n\n<p><mark style=\"background-color:rgba(0, 0, 0, 0)\" class=\"has-inline-color has-luminous-vivid-amber-color\">df <\/mark>-h<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Ensure no partitions (especially <code>\/home<\/code>, <code>\/var<\/code>) are 100% full<\/li>\n<\/ul>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h3 class=\"wp-block-heading\">\ud83d\udd39 8. <strong>Test with External Sender<\/strong><\/h3>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Send test email from Gmail, Outlook, etc.<\/li>\n\n\n\n<li>Confirm NDR (bounce) or missing silently<\/li>\n<\/ul>\n","protected":false},"excerpt":{"rendered":"<p>\u2705 1. DNS and MX Records \u2705 2. Mail Server Logs Check these log files for errors: Use: tail -f \/var\/log\/exim_mainlog \u2705 3. Firewall and Port Access \u2705 4. Email Account Configuration \u2705 5. Spam or Blacklist Issues \u2705 6. Check Email Routing in cPanel \u2705 7. Disk Space df -h ====================================================================== \u2705 Incoming Email [&hellip;]<\/p>\n","protected":false},"author":1,"featured_media":349,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[4,11],"tags":[351,187,348,350,343,347,345,344,346,349],"class_list":["post-348","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-cpanel","category-email-problems","tag-disk-space","tag-dns","tag-email-account-configuration","tag-email-routing","tag-facing-incoming-email-issue","tag-firewall","tag-mail-server-logs","tag-mx-records","tag-port","tag-spam-or-blacklist-issues"],"_links":{"self":[{"href":"https:\/\/www.24x7serverguard.com\/blog\/wp-json\/wp\/v2\/posts\/348","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.24x7serverguard.com\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.24x7serverguard.com\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.24x7serverguard.com\/blog\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.24x7serverguard.com\/blog\/wp-json\/wp\/v2\/comments?post=348"}],"version-history":[{"count":1,"href":"https:\/\/www.24x7serverguard.com\/blog\/wp-json\/wp\/v2\/posts\/348\/revisions"}],"predecessor-version":[{"id":350,"href":"https:\/\/www.24x7serverguard.com\/blog\/wp-json\/wp\/v2\/posts\/348\/revisions\/350"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.24x7serverguard.com\/blog\/wp-json\/wp\/v2\/media\/349"}],"wp:attachment":[{"href":"https:\/\/www.24x7serverguard.com\/blog\/wp-json\/wp\/v2\/media?parent=348"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.24x7serverguard.com\/blog\/wp-json\/wp\/v2\/categories?post=348"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.24x7serverguard.com\/blog\/wp-json\/wp\/v2\/tags?post=348"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}