Measure and manage
Deliverability
Deliverability is whether your email reaches the inbox instead of spam. It is the quiet factor behind every result, and it is mostly in your control.
About 9 min read
What affects deliverability
- Sender reputation: how mailbox providers rate your domain and account based on past behavior.
- List quality: sending to valid, relevant addresses. Bad lists cause bounces, which hurt reputation.
- Engagement: replies and opens tell providers your mail is wanted. Spam complaints tell them the opposite.
- Volume and pattern: steady, human-paced sending looks trustworthy. Sudden spikes look like spam.
- Authentication: correct domain records prove your mail is really from you.
Set up domain authentication
Before you send at any real volume, set up the three records that prove your identity to mailbox providers. You add these with your domain provider:
- SPF: lists the services allowed to send for your domain.
- DKIM: adds a signature that proves a message was not altered.
- DMARC: tells providers what to do with mail that fails the checks above.
This is the highest-value setup step
Email without SPF and DKIM is far more likely to land in spam. If you do one technical thing before sending, do this.Warm up a new mailbox
A mailbox with little sending history has no reputation yet, so providers watch it closely. Build trust gradually:
- Start with a low daily limit, for example ten to twenty emails a day.
- Increase slowly over several weeks as replies come in and bounces stay low.
- Keep early sends to your most relevant, most likely to reply contacts.
Keep your reputation healthy
Watch your bounce rate
A bounce rate above about three percent is a signal to stop and clean your list. OSENBOLT flags this for you and marks invalid addresses so you stop sending to them automatically.
Respect the limits and windows
The daily limits and sending windows exist to protect you. Raising a limit too fast or sending at odd hours works against your reputation. See Mailboxes.
Honor opt-outs immediately
Every campaign email includes an unsubscribe option. When someone opts out, they are removed from sending at once. Honoring this keeps complaints low and keeps you compliant.
If your deliverability drops
- Pause sending and look at your recent bounce rate and any complaints.
- Clean your list and remove risky addresses before resuming.
- Lower your daily limit and rebuild slowly, as if warming up again.
- Confirm your SPF, DKIM, and DMARC records are still correct.