When you upload contacts into EmailBison, you'll notice that certain tags are automatically added. These tags indicate the Email Service Provider (ESP) or spam filtering service your contacts are using. They’re designed to help you make smarter deliverability decisions and create more targeted campaigns.
These tags help you identify which provider your contact’s email is hosted on. For example, a contact with a Gmail address will be tagged with Google.
This allows you to:
Segment your campaigns by ESP
Run experiments or control sending volumes based on deliverability behavior
Group all Google-hosted emails into a single campaign if needed
Segmenting by ESP is especially useful if you want more control over how each provider treats your emails.
You may also see tags like:
Proofpoint
Barracuda
Mimecast
These don’t represent email providers — they indicate that the contact’s inbox is protected by a third-party spam filter.
Why does this matter? These filters are much stricter than standard ESPs. If even a few people behind one of these filters (like Proofpoint) report your emails as spam, it can cause all future emails from your domain to land in spam across that entire filter network.
Segment these contacts into separate campaigns
Use a different set of inboxes to email them
Monitor bounce rates and replies carefully
Treat these campaigns with extra care to avoid blocks
