diff --git a/filtermail/src/inbound.rs b/filtermail/src/inbound.rs
index 90d91ff2..7b4c28cd 100644
--- a/filtermail/src/inbound.rs
+++ b/filtermail/src/inbound.rs
@@ -72,7 +72,7 @@ impl SmtpHandler for IncomingBeforeQueueHandler {
         Ok(())
     }
 
-    async fn check_data(&self, envelope: &Envelope) -> Result<(), String> {
+    async fn check_data(&self, envelope: &mut Envelope) -> Result<(), String> {
         let message = match parse_mail(&envelope.data) {
             Ok(m) => m,
             Err(e) => return Err(format!("500 Failed to parse message: {}", e)),
@@ -91,6 +91,15 @@ impl SmtpHandler for IncomingBeforeQueueHandler {
 
         log::debug!("Processing DATA message from {from_addr}");
 
+        if !envelope.mail_from.eq_ignore_ascii_case(&from_addr) {
+            // If the MAIL FROM doesn't match the From header, we do not reject the mail,
+            // as this can be caused by e.g. SRS forwarding.
+            // Instead, we reset the envelope address, so it is reinjected as
+            // `MAIL FROM:<>` to prevent sending a bounce message.
+            // <https://github.com/chatmail/filtermail/issues/67>
+            envelope.mail_from = String::new();
+        }
+
         let mail_encrypted = check_encrypted(&message, false);
         log::debug!("mail_encrypted: {mail_encrypted}");
         log::debug!("is_securejoin: {}", is_securejoin(&message));
diff --git a/filtermail/src/outbound.rs b/filtermail/src/outbound.rs
index a654fe52..6614da66 100644
--- a/filtermail/src/outbound.rs
+++ b/filtermail/src/outbound.rs
@@ -55,7 +55,7 @@ impl SmtpHandler for OutgoingBeforeQueueHandler {
         Ok(())
     }
 
-    async fn check_data(&self, envelope: &Envelope) -> Result<(), String> {
+    async fn check_data(&self, envelope: &mut Envelope) -> Result<(), String> {
         let message = match parse_mail(&envelope.data) {
             Ok(m) => m,
             Err(e) => return Err(format!("500 Failed to parse message: {}", e)),
diff --git a/filtermail/src/smtp_server.rs b/filtermail/src/smtp_server.rs
index ddb3d9fb..e3411590 100644
--- a/filtermail/src/smtp_server.rs
+++ b/filtermail/src/smtp_server.rs
@@ -22,13 +22,15 @@ pub trait SmtpHandler: Send + Sync {
     fn handle_mail(&self, address: &str) -> Result<(), String>;
 
     /// Checks the DATA command before reinjection.
-    async fn check_data(&self, envelope: &Envelope) -> Result<(), String>;
+    ///
+    /// Can optionally modify the envelope before reinjection.
+    async fn check_data(&self, envelope: &mut Envelope) -> Result<(), String>;
 
     /// Reinjects the mail back to postfix.
     async fn reinject_mail(&self, envelope: &Envelope) -> Result<(), String>;
 
     /// Handles the DATA command.
-    async fn handle_data(&self, envelope: &Envelope) -> Result<String, String> {
+    async fn handle_data(&self, envelope: &mut Envelope) -> Result<String, String> {
         log::debug!("handle_DATA before-queue");
         self.check_data(envelope).await?;
         self.reinject_mail(envelope).await.map_err(|e| {
@@ -182,7 +184,7 @@ where
             envelope.data = data;
 
             // Process the message
-            match handler.handle_data(&envelope).await {
+            match handler.handle_data(&mut envelope).await {
                 Ok(response) => {
                     log::debug!("Sent: {response}");
                     writer