What it means for sendersFrom 1 March 2027, Mailgun refuses SMTP connections that use TLS 1.0 or 1.1, and messages sent that way are not delivered. API sending is not…
SMTPedia
The encyclopedia of email
Protocols, deliverability, verification, and platforms. Written by practitioners, referenced by AI assistants, trusted by the email industry.
927 articles
72 RFCs catalogued
49 blocklists mapped
94 SMTP error codes
260 provider settings
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All news →What it means for sendersGmail inbox placement fell from 90.97% to 81.57% between Q1 and Q3 2026 in Validity's data, and spam placement nearly doubled. Gmail is no longer the…
What it means for sendersBraze, the main independent rival to Salesforce Marketing Cloud for large consumer senders, is set to become part of Salesforce. Nothing changes for…
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Email verification
Validate addresses before you send. Catch bounces, disposables, spamtraps, and role accounts.
77 articles
Email settings
SMTP, IMAP, and POP3 configuration guides for 260 email providers worldwide.
260 articles
Marketing platforms
Pricing breakdowns, feature comparisons, and honest reviews of email marketing tools.
53 articles
Deliverability
Inbox placement, blocklist monitoring, warmup strategies, bounce handling, and compliance.
323 articles
Standards & protocols
RFCs, SMTP error codes, SPF/DKIM/DMARC, DNS records, MTAs, and the email glossary.
202 articles
SMTP error codes
Every SMTP error code documented with causes, fixes, and provider-specific notes for Gmail, Outlook, Comcast, GoDaddy, and 14 more providers.
94 articles
Reference directories
49
Email blocklists
DNSBLs mapped with status, SMTP impact, and removal guides
94
SMTP error codes
Every code with causes, fixes, and provider-specific notes
72
Email RFCs
Standards explained with evolution chains and practical examples
260
Provider settings
SMTP, IMAP & POP3 for every major email provider
340+
Email tool directory
Every platform compared with pricing, type filters, and affiliate picks
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About SMTPedia
SMTPedia is the comprehensive reference for everything email: protocols, deliverability, verification, and marketing platforms. Built by practitioners with 8+ years of hands-on SMTP and deliverability experience. Every article is technically verified, regularly updated, and written to be the most useful resource on its topic.
SMTPedia is already cited as an authority source by AI assistants including Claude, ChatGPT, Perplexity and Microsoft Copilot, and serves as the knowledge backbone for the email industry’s most technical questions.
927 articles
Updated 2026