Solutions / Forwarding & Delegated Sending
Forwarding is the hardest thing in email. We made it a product feature.
Shared inboxes, alias services, send-as-me products, CRM mail sync, assistant tools that answer on a user's behalf. Any product that moves mail between identities collides head-on with modern authentication. Most break DMARC and strand replies. Ours don't.
The context
Why forwarding fights modern authentication.
Forwarding is as old as email itself. For the first few decades of the protocol, passing a message along was completely normal: a server simply re-sent it, and nobody asked questions. Then spoofing became an industry, and the security measures bolted on to stop it (SPF in the 2000s, DKIM after, DMARC on top) all share one assumption: the server transmitting a message should be authorized by the domain in its From line. That assumption is exactly what forwarding violates, and the protocols cannot tell a helpful forwarder from an attacker. So a naive forward fails SPF, often breaks the original DKIM signature in handling, fails DMARC alignment, and lands in spam or gets rejected outright. This is why forwarded mail “mysteriously” stopped working over the last decade. Email’s oldest habit and email’s newest security are simply at war, and your product is standing between them.
The robust solutions involve careful identity handling. Re-author the message under an identity you can legitimately authenticate. Preserve the parts humans care about: who it’s from, who to reply to, the thread. Re-sign cleanly so exactly one valid signature arrives. Every detail matters here. A duplicated Message-ID header, a stale broken signature left next to a new one, a Reply-To that drops the original sender. Each one is a deliverability or usability failure waiting in production.
Underneath that, delegated-sending products are multi-tenant senders whether they admit it or not. Every user is an identity with its own behavior and its own risk. The platform needs per-identity reputation, per-identity rate gates, suppression no user can route around, and real mailboxes when the product’s identities must also receive.
Your challenges
Where forwarding products break.
Forwarded mail lands in spam because SPF, DKIM, and DMARC weren’t designed for what your product does. Your users blame your product.
Replies to forwarded or delegated mail go to the wrong place, breaking threads and trust.
One user’s behavior, or one compromised account, damages sending reputation shared by all your users.
Your identities can send but not receive, so bounces, replies, and out-of-office notices disappear.
Every receiver-side authentication change threatens to break your core feature overnight.
How Egressif helps
What changes when identity handling is enforcement-grade.
DMARC-surviving forwarding
Forwarded and recrafted mail is re-authored under properly authenticated identities, with the originals preserved where humans need them: display names, reply paths, threads. Signatures are re-applied cleanly, so exactly one valid, aligned signature arrives.
Reply paths that survive the trip
Reply-To handling preserves the original correspondents through the forward. "Reply" reaches the human who wrote the message. That is the difference between a delegation product and a dead-letter office.
Header hygiene under modification
Message-ID handling, duplicate-header collapse, and signature replacement are done correctly on every modified message. These are the quiet details strict receivers reject mail over.
Per-user identity isolation
Each user’s sending runs as its own identity with its own reputation and rate budget. One compromised account is one contained identity, not a product-wide placement incident.
Receiving-capable identities
Hosted mailboxes (IMAP/SMTP/JMAP) give your product’s identities a real receiving side. Replies, bounces, and threads land where your product can use them, with server-side filtering to route what arrives.
We track the receivers so you don’t
When mailbox providers tighten authentication or change forwarding treatment, that’s our operational problem to absorb. Your feature keeps working while competitors scramble.
Two forwards
Same message. Opposite outcomes.
FAQ
Forwarding, answered honestly.
Does the recipient see the original sender or our identity?
The honest trade-off: to pass DMARC, the visible From must be an aligned identity, so the recipient sees that identity as the sender, with the original parties preserved in the reply path. Replies route back correctly and threads hold together. It is the difference between mail that lands with a footnote and mail that vanishes.
Can each of our users get their own sending identity?
Yes, programmatically. Identities and mailboxes provision through the API as part of your signup flow, each with aligned authentication and its own reputation. One user’s behavior degrades their identity, not your product’s domains and not your other users.
What happens when a provider tightens DMARC handling again?
For you, nothing. Our identity handling is built to enforcement-grade rules rather than current leniency, which is why the 2024-era tightenings were non-events here. When the next one comes, you read about it instead of refactoring under incident pressure.
Do forwarded replies actually work?
Yes. Reply paths are preserved through the re-authoring, so when the recipient hits reply, it reaches the original party and the thread stays intact. We treat broken replies as a defect, not a known limitation.
Can we run this under our own brand and domains?
Yes. Your domains, your product, your users. We are the infrastructure underneath: authentication, forwarding mechanics, reputation isolation, with every delivery outcome on record and a feed into your backend where you can use one. Your users never see us, which is how infrastructure should behave.
Related reading
Go deeper in the reference library
The problem
Your send-as-user feature worked for two years. Then a major provider tightened DMARC handling and your forwarded mail started bouncing with "550 5.7.509 unauthenticated email is not accepted". Support tickets tripled overnight, and the fix meant re-architecting identity handling under incident pressure.
With Egressif
On Egressif, identity handling was enforcement-grade from day one: aligned authentication on every outbound message regardless of origin. The provider’s change was a non-event. You read about competitors’ outages on a forum.
Build on forwarding that actually works.
Domains, rough volume, current providers, and what hurts. You will get a straight answer on fit, and a real number, in one conversation.