Images are not attached to the signature in the onMessageSend event in Outlook Online and the new Outlook #4716
Description
Provide required information needed to triage your issue
We are listening to the "OnMessageSend" event in our Outlook addin. While the message is send, we are inserting the signature for the user. We realized that in Office Online (and in the new Outlook) inline images are missing in the received signature.
- When inserting the signature with another event like on "OnMessageNew" in Office Online the inline image is shown successfully.
- When using the classic Outlook App on Windows the signature insertion with inline images is also working sucessfully with the "OnMessageSend" event.
Your Environment
- Platform: Office on the web / new Outlook
- Host: Outlook
- Operating System: Windows 11
- Browser: Chrome
Expected behavior
Inline images in signatures shoud be shown to the mail recipient.
Current behavior
When inserting the Signature "OnMessageNew" the signature looks like this
When inserting the signature again with the "OnMessageSend" event the received signature looks like this
Link to live example(s)
Run following code when the "OnMessageSend" event is triggered.
function testOnSend() {
const signature = `<p>Greetings John Doe</p>
<img src="cid:homer.jpg" width="100" />`;
if (!Office.context.mailbox.item) {
return;
}
const item = Office.context.mailbox.item;
return new Promise(resolve => {
item.addFileAttachmentFromBase64Async(
imageBase64,
'homer.jpg',
{ isInline: true },
() => {
item.body.setSignatureAsync(
signature,
{
coercionType: Office.CoercionType.Html,
},
() => resolve(true),
);
},
);
});
}
await testOnSend();