Transactional email carries password resets, confirmations and receipts. When it lands in spam, users conclude your product is broken — and for a password reset, they are right. Getting it to the inbox is a set of specific, checkable steps.

Authenticate properly

  • SPF: authorise the services permitted to send for your domain. Watch the ten-lookup limit.
  • DKIM: publish the key so receivers can verify messages were not altered in transit.
  • DMARC: state what to do when checks fail. Start at p=none while you read the reports, then move to quarantine and reject.

Adding a sending provider means adding DNS records. Do that carefully alongside your existing mail: breaking the MX records that deliver your incoming mail is a far worse outcome than a few messages in spam.

Separate your streams

Send marketing from a different subdomain to transactional mail. If a campaign generates complaints, it should not damage the reputation of the domain that delivers password resets. Many teams discover this connection only after a newsletter has poisoned their receipts.

Content matters less than people think, but it matters

  • Always send a plain-text alternative alongside the HTML.
  • Avoid link shorteners and redirect chains; link to your own domain.
  • Keep image weight moderate and never send an email that is a single image.
  • Use a From address that is a real, monitored mailbox. Replies reaching nobody is both bad practice and a signal.

Instrument it

Log every send: recipient, type, timestamp, outcome and provider error. When a customer says they did not receive a code, you should be able to answer in seconds whether it was sent, accepted or rejected — and why. Without that log you are guessing, and the guess is usually wrong.

Warm a new domain

A domain that has never sent mail suddenly emitting thousands of messages looks exactly like a compromised one. Increase volume gradually over the first weeks, watch bounce and complaint rates, and remove invalid addresses quickly — persistent bounces damage reputation faster than almost anything else.