What Is Sender Reputation? Domain vs IP and How It Is Built

Sender reputation is the trust that receiving mail systems assign to the identities behind an email, mainly the sending IP address and the sending domain, based on how mail from those identities has been treated in the past. Complaints, bounces, spam trap hits and blocklist entries lower it; mail that people open, reply to and keep raises it. Reputation decides whether a well-formed, authenticated message lands in the inbox or in spam.

Quick summary

• IP reputation belongs to the server address that connects to the receiver. It is shared by everyone sending through that IP, so a hosted provider manages it for all customers.
• Domain reputation belongs to the domain in the From header, the DKIM d= tag and the Return-Path. It follows you whichever provider or IP you send from, and it is the one a small business controls.
• Modern receivers weight domain reputation more heavily than they used to, precisely because DKIM and DMARC make the domain a reliable identity.
• Link domains inside the body carry their own reputation. A clean sender linking to an abused shortener inherits some of the damage.
• Authenticate everything: aligned SPF and DKIM with a published DMARC record. Without this, receivers cannot attribute good behaviour to your domain.

IP reputation vs domain reputation

• IP reputation belongs to the server address that connects to the receiver. It is shared by everyone sending through that IP, so a hosted provider manages it for all customers.
• Domain reputation belongs to the domain in the From header, the DKIM d= tag and the Return-Path. It follows you whichever provider or IP you send from, and it is the one a small business controls.
• Modern receivers weight domain reputation more heavily than they used to, precisely because DKIM and DMARC make the domain a reliable identity.
• Link domains inside the body carry their own reputation. A clean sender linking to an abused shortener inherits some of the damage.

What builds reputation

1. Authenticate everything: aligned SPF and DKIM with a published DMARC record. Without this, receivers cannot attribute good behaviour to your domain.
2. Send to people who asked. Sign-ups, customers, and replies to your own outreach, not purchased or scraped lists.
3. Keep bounces low by removing addresses that hard bounce immediately and pausing repeated soft bounces.
4. Keep complaints low, well under 0.3% at Gmail, by making it obvious who you are and easy to opt out.
5. Be consistent. Steady volume from the same domain beats a silent month followed by a blast.
6. Give it time. A new domain has no history; weeks of normal correspondence is what earns trust.

Example: what Google Postmaster Tools shows

Domain reputation:  Bad / Low / Medium / High
IP reputation:      per sending IP, same scale
Spam rate:          % of delivered mail marked as spam by users (keep < 0.3%)
Authentication:     % of mail passing SPF, DKIM, DMARC
Encryption:         % of inbound mail delivered over TLS

Requires: a DNS TXT verification record for your domain and meaningful volume to Gmail

How to check your reputation

• Google Postmaster Tools: add and verify your domain to see the dashboards above.
• Microsoft SNDS: for IP-level data if you operate your own sending IPs; not needed with a hosted provider.
• Blocklist checks at MXToolbox or Spamhaus for both your domain and the sending IP.
• Your own delivery logs: 4xx deferrals mentioning reputation or rate limits are the earliest warning.
• DMARC aggregate reports: show whether unknown sources are sending as your domain and dragging it down.

Common ways reputation is damaged

• A compromised mailbox sending spam overnight. Strong unique passwords per mailbox prevent most of this.
• A cold outreach campaign from the main domain, generating complaints that affect invoices and support mail too.
• Reusing an old list where many addresses have become spam traps.
• Switching providers repeatedly, which resets IP reputation each time while the domain problems travel with you.
• Sending marketing and transactional mail from one identity so a bad campaign harms password resets.

Reputation and OquMail

IP reputation is managed by OquMail, whose sending servers have correct reverse DNS and are monitored. Domain reputation starts with authentication, and the OquMail guided setup with live DNS verification gets SPF, DKIM and DMARC right the first time. From there, use mailboxes for conversations and the send API for transactional messages, and read the per-message delivery logs, where a reputation-related deferral shows up long before a hard block.

Common questions

How long does it take to build reputation on a new domain?

There is no fixed period. Normal business correspondence for a few weeks usually establishes a neutral-to-good standing at the major providers.

Does reputation transfer if I change email providers?

Domain reputation does; IP reputation does not. Keeping DKIM signing on your own domain across the move preserves the history.

Can I buy or reset reputation?

No. A new domain starts at zero and a burned domain recovers only through sustained good behaviour, if at all.