TPH Inbound Email Codes



TPH Error CodesDefinitionSMTP Code RelationResolution
  • TPH1101
  • Sender IP is on DNS based allow list 
  • 250
The sender's IP will always be allowed
  • TPH1102
  • Sender is allowed
  • 250
The sender will always be allowed
  • TPH1261
  • Recipient is unknown
  • 550
The recipient is unknown, please check the email address.
  • TPH1451
  • Sender + IP has not been seen before and it is Greylisted
  • 451
Greylisting is a method of defending e-mail users against spam. A mail transfer agent (MTA) using greylisting will "temporarily reject" any email from a sender it does not recognize.
  • TPH1551
  • The specified attachment is not allowed
  • 554
The sender's attachment does not meet the requirements and will be denied.
  • TPH1552
  • The specified mime type is not allowed
  • 554
The mime (attachment) type is not supported. eg .html
  • TPH1553
  • Message is rejected because of invalid or not allowed HELO used
  • 501
Incorrect HELO process used, the message will be rejected
  • TPH1554
  • IP is listed in a DNS based deny list
  • 550
The senders IP is listed in a DNS based deny list and will be rejected.
  • TPH1555
  • Too many errors eg too many unknown recipients
  • 452
  • 540
The message could be temporarily rejected or rejected because there are too many unknown recipients.
  • TPH1556
  • Message is considered to be spam
  • 552
  • 554
The message has been scanned and believed to contain spam.
  • TPH1557

  • Sender email address is not locally known


  • 551
The sender's email address does not exist as it is not known.
  • TPH1558
  • Sender domain is not found
  • 550
The sender's domain does not exist or is temporarily down.
  • TPH1559
  •  3rd party relaying
  • 554
  • 553
The sender s relaying through a 3rd party and will be detected as malicious.
  • TPH1560
  • Invalid characters found in the local_part i.e. first part of the email address
  • 554
  • 554
The sender has used special characters in his header.
  • TPH1561
  • Header Checks failed
  • 552
  • 554
The header has been scanned and has been detected as spam.
  • TPH1562
  • Message contained a virus

  • 552
The message has been scanned and it contains a virus.
  • TPH1563
  • Message matches impersonation rules
  • 552
The message matches impersonation checks