SMTP & API
How do I set up a webhook in Mailpro?
To set up a webhook, register an endpoint URL on your server that Mailpro can call whenever an email event...
Read moreHow do I integrate Mailpro with WordPress?
To integrate Mailpro with WordPress, route your site’s outgoing email through Mailpro’s SMTP server — either with the Mailpro WordPress...
Read moreIs Port 587 Always Encrypted?
Short answer: Port 587 is not encrypted by default — but it is the standard port for encrypted SMTP submission...
Read moreHow to Check Your SMTP Connection
If your emails aren't going out, the first thing to test is the SMTP connection itself. A 30-second check tells...
Read moreWhat is My SMTP Username and Password?
Your SMTP username and password are the credentials your email client or app uses to authenticate with the SMTP server...
Read moreWhere Do I Find My SMTP Server in Mailpro?
Your Mailpro SMTP server details are everything you need to send transactional or marketing email from your app, CRM, CMS...
Read moreWhat Is DNS Error 5.7.26 and How to Fix It?
DNS error 5.7.26 is the bounce code Gmail returns when an incoming message fails its sender authentication checks. The address...
Read moreHow to Fix Error 5.1.1 (User Unknown)
Code 5.1.1 « User unknown » (sometimes returned with 550 5.1.1) means the receiving server cannot find the user part of the...
Read moreHow to Fix Error 5.7.1 (Relay Access Denied)
Code 5.7.1 « Relay access denied » means the SMTP server you connected to refuses to forward your message to...
Read moreHow to Fix Error 530 (Authentication Required)
SMTP error 530 means: I won’t accept your message until you log in. The server is asking for authentication and...
Read moreHow to Fix Error 552 (Storage Limit Exceeded)
SMTP error 552 means the destination has refused the message because it exceeded a storage or size limit. Two distinct...
Read moreHow to Fix Error 451 (Local Policy Violation or Greylisting)
SMTP error 451 is a soft bounce: the receiving server is asking to try again later. The two most common...
Read moreHow to Fix Error 553 (Mailbox Name Not Allowed)
SMTP error 553 means the receiving server has rejected the mailbox name in the envelope. Either the address is malformed...
Read moreHow to Fix Error 4xx (Temporary Failure)
An SMTP 4xx code is a temporary failure: the receiving server is saying « not now, try again later ». The address...
Read moreWhat Are the Most Common SMTP Errors?
SMTP errors fall into two families: 4xx codes are temporary (retry), 5xx codes are permanent (don’t retry until you fix...
Read moreHow to Solve Error 550 (Requested Action Not Taken – Mailbox Unavailable)?
SMTP code 550 is a hard bounce: the receiving server has refused the message. The text right after the code...
Read moreHow to Solve a DNS Code 5.7.26 Error?
Error 5.7.26 is a Gmail rejection that means: this message did not pass authentication. Since Google’s 2024 sender requirements, any...
Read moreWhat Is a Monitoring DMARC Policy?
A monitoring DMARC policy is the safest way to start with DMARC. You publish a TXT record with p=none, which...
Read moreHow to Make Sure Password Reset Emails Don’t Go to Spam
To stop password reset emails from landing in spam, you need to combine three things: technical authentication, content discipline and...
Read moreWhat Is a Password Reset Email?
A password reset email is the automated message a service sends when a user clicks « forgot password ». It...
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