SMTP Error Code 554

smtp;554 5.7.1 <[email protected]>: 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 <[email protected]>: 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 5.2.121 The sender has exceeded the limit for the number of messages they can send to this recipient per hour. For more information go to http://go.microsoft.com/fwlink/?LinkId=526653. [#.prod.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 (