MailerSend

What do you set up before customers get mail?

Use MailerSend’s trial domain to check a connection. For customer mail, confirm the account can send and verify a domain you control. Add the records MailerSend supplies at the service where your domain is managed.

Choose the From address on the verified domain. Then give your app either an API key or SMTP settings. SMTP is the standard way for an app to hand mail to a mail server. Keep either credential on the server side, where visitors cannot see it.

Can MailerSend’s sandbox send to a real inbox?

Yes. MailerSend’s Sandbox mode can deliver to real addresses. The trial domain can send to up to two distinct recipients, so a trial receipt can still land in someone’s inbox.

1. 1
   Trace a fictional order on paper

   Write the From address, the single intended test recipient and the order number your app should use. Sketch what you would look for in Activity and note which status would prove the recipient’s mail server accepted it. You can do this without sending anything.
2. 2
   Check the test copy before any real delivery

   If you choose to test delivery, first verify that a disposable copy of the app uses the trial-domain credential and fictional records. Inspect the actual recipient fields, including any copied addresses, and make sure any callbacks or notifications stay in the test setup. Use only an inbox you control and omit personal information, working reset links and attachments. If you cannot verify the setup, stick to the paper check.
3. 3
   Follow one result

   If using the API, record the message ID returned when available. A successful request may only mean the receipt is queued. Find the receipt in Activity and check the test inbox separately.

Where do you look when the receipt never arrives?

Search Activity by recipient, subject or message ID. Queued means MailerSend is still processing the request. Sent means it is waiting for the receiving server’s response. Delivered tells you the server accepted it. Check the inbox separately if the recipient still cannot find it.

If the message is rejected, check the timeline for a bounce and the Suppressions page for a reason to skip that address. An invalid address needs correction. A blocked address needs the cause resolved before you attempt another send.

What changes between Sandbox mode, Free and a paid plan?

Sandbox mode allows 100 emails per month and 100 API requests per day. The approved Free plan lists 500 emails per month and 100 emails per day. Activating Free requires billing details.

On paid plans that permit extra usage, the rate is priced per 1,000 emails. If you move providers, export the filtered activity you need as CSV while it is still available. Keep copies of your templates and sender settings in a place you control.