What is sender reputation?

It's the trust score mailbox providers assign to your sending domain based on how recipients react to your mail. Strong engagement and low complaints and bounces earn inbox placement; spam complaints, dead addresses, and spam-trap hits push you toward the spam folder or an outright block.

Should I delete subscribers who don't engage?

You don't have to. Boostmail never charges per contact, so a quiet subscriber costs nothing to keep. What matters for reputation is who you send to: target engaged segments for most campaigns, and email long-inactive contacts sparingly, for example with an occasional re-engagement message.

What's an unsubscribe versus a spam complaint?

An unsubscribe is a normal, healthy exit and is far better than a spam complaint, which actively harms your reputation. Boostmail includes a one-click unsubscribe so unhappy recipients can opt out easily instead of hitting 'report spam'.

Do I need to warm up a new domain?

It's good practice when you're sending in volume from a brand-new domain. Start with your most engaged subscribers and increase volume over days and weeks, so providers see a steady, trustworthy pattern rather than a sudden spike.

Improve your sender reputation

Reviewed by Eran Betzalel, founder · 2026-09-30

Your sender reputation is the trust mailbox providers place in your domain based on how people react to your email, and it is what decides whether you reach the inbox or the spam folder. Boostmail handles the mechanics for you, automatic bounce and complaint suppression and a one-click unsubscribe, but the day-to-day habits below are what keep that reputation healthy. The core idea is simple: send wanted mail to engaged people, and stop sending to addresses that bounce or complain.

Keep your list clean

List hygiene is the foundation of good deliverability:

Only mail people who opted in. Never send to purchased or scraped lists. This starts at import, where you should bring in consented contacts only.
Stop mailing hard bounces. A hard bounce means the address is invalid. Continuing to mail it signals to providers that you don’t maintain your list. Boostmail suppresses bounced addresses automatically so they stop receiving mail.
Send to engaged segments. Target most campaigns at subscribers who open and click, and email long-inactive contacts only occasionally. Because Boostmail never charges per contact, you don’t need to delete quiet subscribers to save money, you simply choose not to email them every time.

Earn engagement

Providers watch how recipients interact with your mail. Opens, clicks, and replies are positive signals; deletions without opening and spam complaints are negative ones. To keep engagement high, send relevant content to well-defined segments, maintain a consistent but not overwhelming cadence, and write subject lines that set honest expectations. Boostmail’s reports show opens, clicks, bounces and complaints per campaign, so you can spot problems early.

Handle complaints and unsubscribes well

A spam complaint hurts far more than an unsubscribe. Every Boostmail email includes a one-click unsubscribe so dissatisfied recipients can opt out instead of reporting you, and addresses that complain are suppressed automatically so you don’t mail them again.

Warm up new domains

If you’re sending volume from a brand-new domain, don’t blast your whole list on day one. Start with your most engaged subscribers and increase volume gradually over days and weeks. A steady, growing pattern looks trustworthy; a sudden spike from a cold domain can look like spam. The same thinking applies when ramping up scheduled sends at scale.

Start with authentication

None of this works without the basics in place. If you haven’t already, authenticate your domain with SPF, DKIM, and DMARC first, it’s the prerequisite for everything above. Learn more about Boostmail’s deliverability features.

Frequently asked questions

What is sender reputation?: It's the trust score mailbox providers assign to your sending domain based on how recipients react to your mail. Strong engagement and low complaints and bounces earn inbox placement; spam complaints, dead addresses, and spam-trap hits push you toward the spam folder or an outright block.
Should I delete subscribers who don't engage?: You don't have to. Boostmail never charges per contact, so a quiet subscriber costs nothing to keep. What matters for reputation is who you send to: target engaged segments for most campaigns, and email long-inactive contacts sparingly, for example with an occasional re-engagement message.
What's an unsubscribe versus a spam complaint?: An unsubscribe is a normal, healthy exit and is far better than a spam complaint, which actively harms your reputation. Boostmail includes a one-click unsubscribe so unhappy recipients can opt out easily instead of hitting 'report spam'.
Do I need to warm up a new domain?: It's good practice when you're sending in volume from a brand-new domain. Start with your most engaged subscribers and increase volume over days and weeks, so providers see a steady, trustworthy pattern rather than a sudden spike.