Getting Started

Welcome to ImprovMX!
Aliases
Catchall & Wildcard Aliases
Null Alias Destination
Redirecting to Multiple Destinations
Regexes in Aliases
Rules Routing
Testing Your Aliases
Viewing MX & SPF records
Webhooks
API Reference

Email Deliverability

Email Logs
Error Codes
Gmail Filters to Prevent Emails Marked As Spam
Soft & Hard bounces
Spamhaus / SpamCop Filtering
Testing Gmail Forwarding

DNS Setup Guides

Amazon Route53
Bluehost
Cloudflare
Combining SPF Records
DigitalOcean
GSuite Legacy Setup
Generic DNS Configuration
Gmail's "send mail as"
GoDaddy
Google Workspace Split Delivery
Hostgator
Hostinger
Microsoft 365 Split Delivery
Namecheap
Netlify
Porkbun
Squarespace
Vercel
White Labeling MX Records
Zoho Mail Split Delivery

SMTP

Introduction to ImprovMX SMTP
Create SMTP Credentials
Adding DKIM and DMARC Records
Apple Mail (MacOS) SMTP
Apple Mail (iOS) SMTP
Gmail SMTP
Microsoft Outlook Incompatibility
Mozilla Thunderbird SMTP

Glossary

IMAP (Internet Message Access Protocol)
MX Records
POP3 (Post Office Protocol v3)
SMTP (Simple Mail Transfer Protocol)

Limits

API Rate Limits
Allowed Attachments
Sending/Receiving Limits
Supported SMTP Ciphers
Using Free Domains on ImprovMX

FAQ

Are you SOC 2 or ISO 27001 compliant?
Can I Whitelist an Email Address?
Can I turn off spam filtering?
Can I use ImprovMX SMTP for bulk mailing or mailing lists?
Can I use MX records from multiple forwarders?
Do you have a bug bounty program?
Do you offer any cheaper plans?
Do you support ARC?
Do you support SRS?
Downloading an Email from ImprovMX Logs
How do I view email headers?
How is incoming email processed?
How to setup a Gmail profile image for your email alias.
I'm getting a "Line too long" error
I'm getting a "Too Much Mail Data" error
ImprovMX IMAP, POP, and Incoming Protocols
No more MXS Domains
Raycast Extension
What does "Invalid DKIM signature" mean?
What is the difference between Forwarding & SMTP?
Why am I getting error: "5.1.9 Domain <domain> is not configured to send emails"?
Why are emails landing in spam?
Why are you not open source?
Why aren't my DNS Records validating?
Why can't I redirect emails to the same domain during account signup?
Why do I see "reverse DNS does not match SMTP banner" for mx1/mx2?
Why does ImprovMX need SPF?

Competitors

ImprovMX vs. addy.io
ImprovMX vs. Cloudflare
ImprovMX vs. Fastmail
ImprovMX vs. ForwardEmail
ImprovMX vs. ForwardMX
ImprovMX vs. Google Workspace
ImprovMX vs. GoDaddy
ImprovMX vs. Mailgun
ImprovMX vs. Mailchimp
ImprovMX vs. Namecheap
ImprovMX vs. Postmark
ImprovMX vs. ProtonMail
ImprovMX vs. Purelymail
ImprovMX vs. Resend
ImprovMX vs. Sendgrid
ImprovMX vs. SimpleLogin
ImprovMX vs. SMTP2GO
ImprovMX vs. Squarespace
ImprovMX vs. Zoho

Strict MX Verification

Get alerts when another MX record outranks ImprovMX.

Strict MX Verification is on by default to alert you if any MX record outranks ImprovMX - useful when ImprovMX is your primary MX. If you use ImprovMX as secondary/failover or in split delivery, another provider should be higher priority, so disable this setting to avoid unnecessary alerts.

When to use which setting:

  • Enable: ImprovMX should be the highest-priority MX for the domain (primary).
  • Disable: ImprovMX is lower-priority by design (failover/split delivery).

How to toggle it:

  1. Log in to ImprovMX and select your domain.
  2. Go to "Custom Settings".
  3. Use the Strict MX Verification toggle to enable or disable.

Still have questions? Feel free to reach out to our support team!