E-mails land in spam or are rejected
SPF, DKIM, DMARC, bounces and the other things that decide whether your mail is delivered.
Messages from your domain end up in the recipients' spam folder, or they are rejected and come back with a bounce. Deliverability depends on a handful of things that receiving mail servers check; go through them in this order.
1. Send through our mail server
Messages that carry your domain in the From address should leave through our SMTP server, mailXXX.mailasp.net, with the login of a mailbox of that domain. Only then do the SPF and DKIM records of your domain apply to them.
- From an application, use the settings in Send e-mails from your application through our SMTP server.
- The From address must be a mailbox or alias of your domain. A message sent "from" a Gmail or Outlook.com address through our server fails the checks of Google and Microsoft.
- Check the delivery log of the domain. If the messages are not there, they were sent through another server — and that server has to be covered by your SPF record.
2. Publish SPF, DKIM and DMARC
| Record | What it does | Where it is set |
|---|---|---|
| SPF | Lists the servers allowed to send for your domain. | TXT record v=spf1 a mx include:spf.mailasp.net ~all — see DNS records for e-mail |
| DKIM | Signs every outgoing message; the receiver verifies the signature. | Switch in the Control Panel — see Enable DKIM |
| DMARC | Tells receivers what to do with messages that fail SPF or DKIM, and sends you reports. | TXT record _dmarc |
If your domain uses our name servers, SPF and DKIM are published for you. Add DMARC yourself; start with a monitoring policy and tighten it once your own mail passes:
Name: _dmarc
Type: TXT
Value: v=DMARC1; p=quarantine; rua=mailto:postmaster@yourdomain.com
Google, Microsoft and Yahoo require SPF and DKIM, and DMARC for anyone sending in volume. Without them, mail is filed as spam or rejected regardless of its content.
Check your setup with MXToolbox or by sending a message to mail-tester.com.
3. Read the bounce
When a server rejects a message, a bounce is delivered to the sender and to postmaster@yourdomain.com. The bounce states the reason, for example:
| Bounce text | Meaning |
|---|---|
550 5.7.1 ... SPF / DMARC |
The DNS records above are missing or wrong. |
550 5.7.1 ... blocked using ... or a blocklist name |
The IP address of the mail server is on a blocklist, usually because another customer sent unsolicited mail. Forward the bounce to us — we handle the delisting. |
550 5.1.1 User unknown |
The recipient address does not exist. |
452 4.2.2 Mailbox full / 4.x.x |
Temporary; the server retries automatically. |
The same reason is shown in the delivery log next to the message.
4. Content and volume
- Send transactional mail (registrations, invoices, notifications) from your domain; send newsletters and bulk campaigns through a dedicated service such as Mailchimp, Brevo or SendGrid. Bulk mail from a shared server hurts the reputation of everyone on it.
- Respect the e-mail service limits. Hitting them delays or drops your messages.
- Use a real sender name, a working reply address and a plain-text part. Avoid link shorteners and attachments in automated mail.
Spam that pretends to come from your domain
Spoofed messages — spam that shows your own address as the sender — are stopped by DMARC with p=reject, together with valid SPF and DKIM. If you keep receiving such messages after the records are in place, send us the full headers of one of them.