Loymax, 2026

Quality of contact information

Data quality is represented as special codes assigned to contact details to indicate data status, reliability, and relevance.

Delivery problem codes that reflect the quality of contact data are shown in the table below.

CodeName
0No errors
1Temporarily unavailable for delivery
2DNS error
3Mailbox is full
4Message length exceeded
5Timeout
6Answering machine is on
30No address specified
31Format error
32Address does not exist
33Cannot be delivered
34Delivery attempts are exhausted
35Blocked by MTA
36Spam complaint
37Blocked by recipient
38Recipient does not accept attachments
39Non-existent domain
50Contact in blacklist

If the recipient's email address does not exist or is unavailable for any reason, the server returns a bounce message indicating the delivery failure. Depending on the cause, bounces are categorized as:

  • Soft bounces — temporary delivery failures corresponding to delivery problem codes from 1 to 29. Messages are still sent to addresses with soft bounces. Each address has an internal counter tracking soft bounces. If there are 7 or more soft bounces within a month, the address receives code 34 (Delivery attempts are exhausted) and this address is permanently excluded from mailings. Customer email addresses with soft bounces are marked in the System with an orange indicator Orange.png.
  • Hard bounces — permanent delivery failures corresponding to codes 30 and above. Addresses with hard bounces are permanently excluded from mailings. Customer email addresses with hard bounces are marked with a red indicator Red.png.
colour_indicators.png

See also the dedicated section for information on warming up IP addresses, getting off blacklists, and other recommendations for high-quality mailings.

Created by Vera Retyeva on 2025/06/11 09:28
Created 2025/06/11 09:28
Last edited 2025/06/11 09:28

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