{"id":19042,"date":"2020-11-20T11:07:38","date_gmt":"2020-11-20T03:07:38","guid":{"rendered":"https:\/\/web.mwwsb.com.my\/pjci\/?post_type=kb&p=19042"},"modified":"2022-09-08T20:13:43","modified_gmt":"2022-09-08T12:13:43","slug":"undeliverable-message-and-451-greylisted","status":"publish","type":"kb","link":"https:\/\/www.casbay.com\/guide\/kb\/undeliverable-message-and-451-greylisted","title":{"rendered":"Undeliverable Message"},"content":{"rendered":"\t\t
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Overview\/Problem of Undeliverable Message<\/h2>\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t
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This article discusses how you can send an email to someone with the same domain name to solve the message that the 451 Greylist system administrator receives. This status will be shown in \u2018451 Greylisted, please try again in XXX seconds\u2019.<\/p>\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t

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What is Greylisting?\n<\/h2>\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t
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Greylisting is one way of stopping \/ reducing spam. Mail servers with the option to delay emails temporarily until posts verify that the message is genuine. In the previous days, most spammers once sent a spam message to a user, so the message wasn\u2019t resentful. However, the greylisting has altered slightly today, and is thus still helpful today with other anti-spam techniques.<\/p>\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t

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How to Fix \u2013 Adjusting your SMTP Authentication<\/h2>\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t
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Your customers must use SMTP<\/a> authentication in order to fix the greylized error for the mail customers. This is a relatively fast solution in Microsoft Outlook 2003, 2007 and 2010.<\/span><\/p>

Your mailbox account configurations need to be adjusted:<\/span><\/p>