What is an email relay service? How it puts distance between you and harassment

An email relay service is a layer that sits between you and the people who send you messages. Instead of giving someone your real email address, you give them a relay address.

Their messages go to the relay first, where they can be screened, filtered, and processed, and then they’re forwarded to your real inbox, or in some cases, a cleaned-up version of each message is forwarded.

Most people encounter the term in a technical context (it’s also used in bulk email sending infrastructure), but for individuals dealing with harassment, an email relay service has a very practical, personal use: it lets you stay contactable without exposing your real inbox or your real address.

How an email relay service works

When you sign up for a relay service, you’re given a dedicated address, something like yourname@fencechat.com or a randomised alias. You share this address with the people you want to hear from, including people whose messages you might want filtered. Our guide on how FenceChat works shows the set-up.

When someone sends a message to that relay address, here’s what happens:

1. The message arrives at the relay server, not your inbox
2. The relay processes the message: this may include AI filtering, archiving, or logging
3. A version of the message (filtered or unfiltered, depending on your settings) is forwarded to your real email address
4. If you reply, the reply goes through the relay so the sender only ever sees the relay address

Your real email address is never visible to the sender at any point in this process.

Email relay vs basic email forwarding

Basic email forwarding, the kind you can set up in Gmail or any webmail provider, moves messages from one inbox to another, unchanged. If you forward your spare address to your main address, you still receive every message in its original form. There’s no filtering, no processing, and no hiding of your main address (some forwarding setups can expose it in message headers). A second phone number has the same limitation for texts.

A relay service adds several layers on top of simple forwarding:

• Filtering: abusive or hostile content is identified and removed before the message reaches you
• Archiving: originals are stored, including content that was filtered out
• Address privacy: your real email is never exposed, even in message headers
• Reply routing: replies appear to come from the relay address, not your real one

The distinction matters most when you’re dealing with harassment. Basic forwarding just moves the problem. A relay with filtering changes what you actually receive. Our guide on how to stop harassing emails covers the other steps.

Communication relay service vs email relay service

You’ll sometimes see the term “communication relay service” used more broadly. This usually refers to a service that handles multiple communication channels (both email and SMS) through a single account.

For people dealing with harassment from an ex-partner or difficult contact who has both their email address and their phone number, a combined relay is considerably more useful. Both channels are filtered through the same system, messages from both channels appear in the same archive, and you manage everything from one place.

An email-only relay handles email messages. A communication relay service handles email and text messages (SMS) together.

Who uses email relay services for harassment

The most common situations where people look for an email relay service to manage harassment include:

• Post-relationship contact: where an ex-partner sends frequent, hostile, or unwanted emails and complete blocking isn’t possible (co-parenting, shared property, legal matters)
• Family disputes: where a family member sends emotionally abusive messages mixed with legitimate communication
• Business disputes: where a former client, employee, or partner continues to make contact in an aggressive or threatening way (see our guides to business dispute communications and difficult business partners)
• Online harassment: where someone has obtained your email address and is sending unwanted or threatening messages

In all these cases, the need is the same: stay contactable, protect your real address, and reduce exposure to abusive content without losing access to legitimate information. The same applies to a landlord and tenant dispute.

The archive: why it matters

One of the most practically important features of a relay service, and one that distinguishes it from a simple spam filter, is the message archive.

When a relay filters out abusive content before forwarding a message, the filtered content still needs to exist somewhere. A well-designed relay service stores the original unfiltered message alongside the cleaned version you receive. This gives you a timestamped record of everything that was sent to you, including content you were shielded from in your inbox.

If you ever need to document a pattern of harassment for a solicitor, mediator, family court, or police, this archive gives you a complete record to work from. You don’t need to have read abusive messages to have a record of them.

What to look for in a relay service

If you’re evaluating relay services specifically for managing harassment or difficult contacts, look for:

• AI-powered filtering: basic keyword blocking is easy to circumvent; you want something that understands context and tone
• Message archiving with originals: you need the unfiltered record, not just the cleaned-up version
• Permanent relay address: changing services shouldn’t mean changing the address you’ve given people
• No participation required: the service should work entirely on your end; the sender doesn’t need to sign up or do anything differently
• SMS as well as email: if the person has your phone number too, handling both channels together is much simpler

Where to get help

These services are free or low-cost. If you or someone else is in danger, call your local emergency number first.

Australia

Privacy

• Office of the Australian Information Commissioner Your privacy rights in Australia.

Online abuse, stalking and cybercrime

• eSafety Commissioner Report serious online abuse and image-based abuse.
• ReportCyber Report cybercrime affecting you or your business.

If you feel unsafe

• Emergency: 000 Police, ambulance or fire, if you or someone else is in danger.
• 1800RESPECT Free, confidential counselling for family, domestic and sexual violence, any time. 1800 737 732.

United States

Privacy

• IdentityTheft.gov Federal help if someone misuses your personal details.

Online abuse, stalking and cybercrime

• Cyber Civil Rights Initiative Support for online and image-based abuse, including a free helpline, any time: 844-878-2274.
• Stalking Prevention, Awareness and Resource Center Information and resources about stalking.
• FBI Internet Crime Complaint Center Report internet crime.

If you feel unsafe

• Emergency: 911 Police, ambulance or fire, if you or someone else is in danger.
• National Domestic Violence Hotline Free, confidential support, any time. Call 1-800-799-7233 or text START to 88788.

United Kingdom

Privacy

• Information Commissioner’s Office Your data protection rights in the UK.

Online abuse, stalking and cybercrime

• National Stalking Helpline Advice for people affected by stalking. 0808 802 0300.
• Victim Support Free support for people affected by crime.

If you feel unsafe

• Emergency: 999 Police, ambulance or fire, if you or someone else is in danger.
• National Domestic Abuse Helpline Free, confidential support, any time. 0808 2000 247.