Start with the messages you actually send

A password reset, an invoice and a permission-based newsletter have different operational needs. Document the message types, normal daily volume, peak hourly traffic and recipient mailbox mix before comparing plans. Separate transactional and marketing streams where appropriate so promotional problems are easier to diagnose and contain.

For the service itself, see our SMTP setup and delivery support. This guide is a selection checklist, not an independent ranking of every provider.

Questions to ask before choosing a plan

  • Integration: Does the service support your application’s SMTP authentication and TLS requirements? If you need an API or event webhooks, verify those capabilities separately rather than assuming SMTP includes them.
  • Capacity: Ask for hourly and daily limits, connection limits, queue behaviour and the policy for temporary deferrals. A plan allowance is not a promise that every recipient will accept that volume.
  • Identity: Confirm who configures sending-domain authentication, return-path and tracking domains, and who retains DNS access when the contract ends.
  • Evidence: Request a sample delivery log with timestamps, message identifiers and recipient-server responses. Confirm retention, export access and how support investigates a failed message.
  • Suppression: Identify whether the provider or your campaign software handles hard bounces, complaints and unsubscribe requests. Test that suppressed recipients cannot re-enter a later campaign accidentally.
  • Costs and support: Compare setup charges, included volume, overages, IP charges and support scope. Ask for escalation arrangements and maintenance expectations in writing.

Dedicated IP or shared sending?

A dedicated IP gives you more control over its sending activity, but also makes reputation management your responsibility. It is not automatically better for a small or irregular programme. Discuss consistent volume, audience permission and past delivery results before choosing; an older IP alone is not evidence of good reputation.

Run a controlled pilot before migrating production

  1. Configure authentication and send representative messages to mailboxes you control. Inspect received headers and verify the intended sender identity.
  2. Test the unsubscribe flow for marketing, bounce handling, links, plain-text content and reply routing.
  3. Use a small, permission-based audience for the pilot. Review recipient-server responses and complaints before changing volume.
  4. Agree on rollback steps and retain your existing suppression list when migrating.

SMTP acceptance, inbox placement and a reader’s response are different outcomes. No provider can guarantee inbox placement, and a single test score does not establish production reputation. Our deliverability consulting page explains the troubleshooting scope.

What to send us for a useful recommendation

Share your application, message types, expected volume, audience acquisition method and a redacted example of any delivery error. Do not send passwords or private recipient lists in an initial enquiry. Review current plans, then request a scope review to confirm configuration, responsibilities and costs before purchase.