Our Mail DNS Records

For your business email (MailLB infrastructure) to work reliably and securely with your domain, the records below must be added to your domain's DNS zone. They tell other servers on the internet where to deliver your email and which servers may send email on your behalf.

MailLB DNS Records

The Copy button next to each value copies it in full, as a single line, so you can paste it straight into your DNS panel.

Before You Enter the Records

• @ stands for your domain itself (e.g. yourdomain.com). Some DNS panels want this field left empty or filled with the full domain name instead.
• Enter the name exactly as shown (_dmarc); most panels append your domain automatically. If yours asks for the full name, add your domain to the end (_dmarc.yourdomain.com).
• A domain must have only one SPF record (a TXT record starting with v=spf1). If you already have one, merge the two into a single record instead of adding a second.
• Delete old MX records that belong to another email provider; otherwise some of your email may still go to the old server.
• You can use a TTL of 3600 (1 hour). Changes can take a few hours to propagate across the internet.

You can check that the records resolve correctly with our MX, SPF, DKIM and DMARC lookup tools.

What Do These Records Do?

MX Records: Where Your Email Is Delivered

An MX (Mail Exchanger) record tells the internet which server should receive email sent to your domain. A server sending you a message first looks up your MX records and then delivers the message to the server they name.

Both MX records point to smx.maillb.com. The one with the lower priority value (10) is the primary; the record with priority 1000 is the backup used when the primary cannot be reached.

SPF Record: Who May Send Email on Your Behalf

SPF (Sender Policy Framework) lists the servers authorized to send email for your domain. The receiving server checks this record to see whether a message came from an authorized server, which makes it harder for others to send forged email in your name.

v=spf1 a mx ip4:185.46.40.0/22 ~all means: the servers in your domain's A and MX records and the MailLB servers in the 185.46.40.0 – 185.46.43.255 range may send email; messages from any other source are treated as suspicious (~all).

DKIM Record: Your Email's Digital Seal

DKIM (DomainKeys Identified Mail) adds a digital signature to every message you send. The receiving server verifies the signature against the public key in the mail._domainkey record; if it is valid, the message was not altered in transit and came from an authorized server.

DMARC Record: What Happens to Messages That Fail

DMARC tells receiving servers what to do with messages that fail SPF and DKIM checks, and lets reports be collected about those messages.

In our record, p=quarantine sends failing messages to quarantine (usually the spam folder), pct=50 applies that policy to half of them, and sp=none takes no action for subdomains. The rua and ruf reports go to MailLB.

A Records: Your Mail Server's Address

An A record points a name to an IP address. Thanks to the imap, pop3 and smtp records, you can use imap.yourdomain.com, pop3.yourdomain.com and smtp.yourdomain.com as server names in your email app (Outlook, Thunderbird, your phone's mail app), and the mail and webmail records let you reach webmail under your own domain. All of them lead to the MailLB server (185.46.43.2).

PTR Record: The IP Address's Identity Card

A PTR (reverse DNS) record shows which name an IP address belongs to, and many mail servers check that the sending IP has a valid PTR record. PTR records are kept by the owner of the IP address, not in your domain's DNS: the PTR records of the MailLB servers are managed by us, so you don't need to add anything.