How can we help you today?
Questions most frequently asked:
How to Integrate Mailpro SMTP with an AI / GPT Operator
Connecting your Mailpro SMTP relay to an AI agent — like ChatGPT Operator, Claude, n8n or your own Python/Node script...
Read moreHow to Fix "DMARC Policy Not Enabled"
If a deliverability tool tells you "DMARC policy not enabled", your DMARC record exists but is set to p=none. That...
Read moreCan I Rent a Fixed IP, and What Are the Terms?
Yes — you can rent a fixed (dedicated) IP for sending campaigns from your Mailpro account. The fixed IP is...
Read moreCan I Add Branching Logic to My Surveys?
Yes — Mailpro surveys support branching logic, so each respondent only sees the questions that apply to them. Based on...
Read moreHow Does Mailpro Ensure the Security of Survey Data?
Mailpro protects survey data on three levels: in transit (SSL/TLS), at rest (encrypted Swiss-hosted databases) and at access (passwords, CAPTCHA,...
Read moreDoes the Survey Tool Provide Analytics and Reporting?
Yes — Mailpro’s survey tool ships with built-in analytics that update in real time. You see how many people opened...
Read moreCan I Customize the Look and Feel of My Surveys?
Yes — surveys built with Mailpro can be styled to match your brand from the cover page to the thank-you...
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 moreWhat Is Eco-Friendly Email Marketing?
Eco-friendly email marketing is the practice of reducing the carbon footprint of your campaigns — lighter emails, cleaner lists, fewer...
Read moreWhat Is a Customer Satisfaction Survey? Definition and Purpose
A customer satisfaction survey is a short questionnaire you send to customers to measure how happy they are with your...
Read moreWhat Is Dark Mode in Mailpro, and When Should I Use It?
Dark Mode in Mailpro is a built-in preview that shows how your newsletter will look in mail clients that switch...
Read more