Entire email chain not included in reply_to_message_id

Question and Answers
1

I’m using reply_to_message_id to reply to an email chain:

message_data = {
"to": to_recipients,
"subject": email_data.subject,
"body": email_data.body,
"reply_to_message_id": reply_to_message_id  # This makes it a reply!
}

However, if the email chain has multiple emails as part of the thread then the email gets correctly added to the email thread but the content of the email only contains the last reply to the email chain (e.g. the one associated to the reply_to_message_id), but does not include all the emails in that email chain (e.g. replies before the reply_to_message_id)

Is there a way to get all the emails to be included when using reply_to_message_id?

2

Hello,

This is expected behavior. The reply_to_message_id parameter handles email threading only (sets In-Reply-To and References headers) - it does not automatically include quoted content from previous messages in your email body.

Email clients handle quoting very differently - some use blockquotes, some use > prefixes, some include HTML styling. By not auto-including quoted content, Nylas gives you control over:

  • Quote formatting (text vs HTML)

  • How much history to include (last message only vs entire thread)

  • Trimming signatures and disclaimers

  • Mobile-friendly condensed replies

Many thanks,
Samuel R.
Support Engineer, Nylas