All tools · page 197

Builds the _mta-sts TXT fields and a policy file skeleton.

Plans testing then enforce mode staging for MTA-STS.

Generates the _smtp._tls rua reporting record.

Plans Outlook autodiscover CNAME and SRV records per domain.

Plans MX preference ordering and fallback host lists.

Checks when secondary MX hosts hurt spam filtering and queueing.

Plans envelope-from domains and subdomains versus visible From headers.

Clarifies From, Reply-To, and Return-Path roles in a reference table.

Generates VERP return-path patterns per list and recipient.

Plans bounce address tag validation scheme and key rotation.

Plans SRS prefix schemes and domains for forwarded mail.

Explains why forwarded mail fails SPF and lists alignment fixes.

References ARC-Authentication-Results, headers, and sealing flow.

Parses pasted headers into a hop table with delays and auth results.

Decodes from, by, with, and via fields on each hop line.

Explains client and MTA fingerprint clues in headers.

Maps 4.x and 5.x enhanced status codes to causes and actions.

Explains 2xx, 4xx, and 5xx semantics and retry rules.

Plans retry intervals that pass greylisting within windows.

Checks anti-NDR steps that stop backscatter to spoofed senders.

Checks list acquisition and hygiene practices that avoid traps.

Builds a day-by-day volume ramp from a starting daily cap.

Converts monthly volume into hourly and per-minute send caps.

Tables typical double-every-few-days warmup milestones.