Note: Newsletter is Pro only feature.
While publishing a post, a writer may choose to send the newsletter to their followers. A newsletter can only sent once for a post. It is possible to send a newsletter for a post which is already published provided the newsletter option was not selected earlier.
If you don't see "Send as newsletter" option then either your account is not a pro account or you have already used the option for this post.
Refer to the steps below to use the newsletter option for already published post.
Step 1: Edit the post

Step 2: Update

Step 3: Choose the newsletter option and click post

For any questions please feel free to use the comments section of this post.
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