SMTP Error Code 554

smtp;554 5.7.1 <example@icloud.com>: Relay access denied

smtp;554 5.7.1 [CS01] Message rejected due to local policy. Please visit https://support.apple.com/en-us/HT204137

Medium severity

host xx.comcast.net [x.xx.xx.xx] SMTP error from remote mail server after initial connection: 554 xx.comcast.net comcast x.xx.xx.xx Comcast requires that all mail servers must have a PTR record with a valid Reverse DNS entry. Currently your mail server does not fill that requirement. For more information, refer to: http://postmaster.comcast.net/smtp-error-codes.php#554

Low severity

554 xx.comcast.net comcast x.xx.xx.xx Comcast block for spam. Please see http://postmaster.comcast.net/smtp-error-codes.php#BL000000

Low severity

smtp;554 5.2.2 <example@free.fr>: Recipient address rejected: Quota exceeded (mailbox for user is full)

Low severity

smtp;554 5.2.122 The recipient has exceeded their limit for the number of messages they can receive per hour. For more information go to http://go.microsoft.com/fwlink/?LinkId=526653. (#) [outlook.com]

smtp;554 5.7.1 Spam message rejected; If this is not spam contact abuse

smtp;554 delivery error: dd This user doesn't have a example.com account (example@example.com) [-9] - example.yahoo.com

smtp;554 delivery error: dd Sorry, your message to example@example.com cannot be delivered. This mailbox is disabled (554.30). - example.yahoo.com

smtp;554 delivery error: dd Requested mail action aborted - example.yahoo.com

smtp;554 5.7.9 Message not accepted for policy reasons. See https://postmaster.yahooinc.com/error-codes

smtp;554 Message not allowed - [PH01] Email not accepted for policy reasons. Please visit https://postmaster.yahooinc.com/error-codes

High severity

smtp;554 Message not allowed - Headers are not RFC compliant[291]

smtp;554 Message not allowed - [299]

smtp;554 delivery error: dd example@example.com is no longer valid. [-20] - example.yahoo.com

smtp;554 5.7.1 [1] Message rejected under suspicion of SPAM; https://ya.cc/1IrBc ##

High severity

smtp;554 5.2.3 MailPolicy violation Error delivering to mailboxes,mx.zoho.com

smtp;554 5.7.1 Email cannot be delivered. Reason: Email flagged as Spam.

smtp;554 rejected due to spam URL in content

High severity

smtp;554 rejecting banned content

High severity

smtp;554 Email rejected due to security policies - https://community.mimecast.com/docs/DOC-1369#554 [#]

smtp;554 5.7.1 <email@example>: Relay access denied

smtp;554 5.7.1 <example@example.com>: Recipient address rejected: BLOCK-SEND-ER.

smtp;554 5.7.1 <example@example.com>: Recipient address rejected: Invalid-Recipient.

smtp;554 5.7.1 <example@example.com>: Recipient address rejected: NO-DOMAIN.

smtp;554 5.7.1 <example@example.com>: Recipient address rejected: BLOCK-RCPT.

smtp;554 5.7.1 <email@example.com>: Recipient address rejected: Not in recipient list