diff --git a/lib/Service/MailTransmission.php b/lib/Service/MailTransmission.php
index be808fc6fb..89e0f15771 100644
--- a/lib/Service/MailTransmission.php
+++ b/lib/Service/MailTransmission.php
@@ -14,6 +14,7 @@
 use Horde_Imap_Client_Data_Fetch;
 use Horde_Imap_Client_Fetch_Query;
 use Horde_Imap_Client_Ids;
+use Horde_Mail_Exception;
 use Horde_Mail_Rfc822_Address;
 use Horde_Mail_Rfc822_List;
 use Horde_Mail_Transport_Null;
@@ -51,6 +52,7 @@
 use OCP\AppFramework\Db\DoesNotExistException;
 use OCP\EventDispatcher\IEventDispatcher;
 use Psr\Log\LoggerInterface;
+use Throwable;
 
 class MailTransmission implements IMailTransmission {
 	private const RETRIABLE_CODES = [
@@ -155,7 +157,7 @@ public function sendMessage(Account $account, LocalMessage $localMessage): void
 		// Send the message
 		try {
 			$mail->send($transport, false, false);
-			$localMessage->setRaw($mail->getRaw(false));
+			$localMessage->setRaw($this->getRawAsString($mail));
 			$localMessage->setStatus(LocalMessage::STATUS_RAW);
 		} catch (Horde_Mime_Exception $e) {
 			if ($e->getPrevious() instanceof Horde_Smtp_Exception) {
@@ -172,13 +174,19 @@ public function sendMessage(Account $account, LocalMessage $localMessage): void
 				$localMessage->setStatus(LocalMessage::STATUS_SMPT_SEND_FAIL);
 				return;
 			}
+
+			try {
+				$localMessage->setRaw($this->getRawAsString($mail));
+			} catch (Throwable) {
+				// Having the raw message is nice for troubleshooting, but should not fail hard.
+			}
 			$localMessage->setStatus(LocalMessage::STATUS_ERROR);
 			return;
 		} finally {
 			if ($transport instanceof Horde_Mail_Transport_Smtphorde) {
 				try {
 					$transport->getSMTPObject()->logout();
-				} catch (\Throwable $e) {
+				} catch (Throwable) {
 					// Handle silently as this is a resource usage optimization
 				}
 			}
@@ -233,7 +241,7 @@ public function saveLocalDraft(Account $account, LocalMessage $message): void {
 			$this->messageMapper->save(
 				$client,
 				$draftsMailbox,
-				$mail->getRaw(false),
+				$this->getRawAsString($mail),
 				[Horde_Imap_Client::FLAG_DRAFT]
 			);
 			$perfLogger->step('save local draft message on IMAP');
@@ -319,7 +327,7 @@ public function saveDraft(NewMessageData $message, ?Message $previousDraft = nul
 			$newUid = $this->messageMapper->save(
 				$client,
 				$draftsMailbox,
-				$mail->getRaw(false),
+				$this->getRawAsString($mail),
 				[Horde_Imap_Client::FLAG_DRAFT]
 			);
 			$perfLogger->step('save message on IMAP');
@@ -437,4 +445,20 @@ public function sendMdn(Account $account, Mailbox $mailbox, Message $message): v
 		}
 	}
 
+	/**
+	 * @throws Horde_Mail_Exception if no base part set
+	 */
+	public function getRawAsString(Horde_Mime_Mail $mail): string {
+		$raw = $mail->getRaw(false);
+		if (is_resource($raw)) {
+			// dead code to make psalm happy
+			// https://github.com/bytestream/Mime/pull/15
+			$raw = stream_get_contents($raw);
+			if ($raw === false) {
+				return '';
+			}
+		}
+		return $raw;
+	}
+
 }