Long emails are clipped (part of the message is cut off) by some email providers. This is not an Envoke specific behaviour, it happens with all emails.
Technically, you can still send these long emails but we suggest you shorten them to ensure your audience sees the entire message and to accurately track email opens.
Example of message clipping:
When emails are clipped:
Your audience doesn't see content past the cutoff point. Sometimes they are presented with a "view entire message" link but not always.
Opens are not tracked for clipped messages because the tracking code at the bottom of emails is cut off. This skews your overall open rate for messages.
When email are clipped and contacts click the "View entire message" link in their inbox they are taken to a page that is hosted by the email provider (such as Gmail), not Envoke. We don't support display issues on these pages.
How to reduce the size of emails?
Shorten your content
Having many content blocks has the most effect in overall email size. Keep content brief, ideally no longer than a 3-4 minute read. Emails are most effective when they provide enough information to readers so they become interested to click through and read the full article on your website.
Use "read more" links
Instead of adding long content directly inside emails, use "read more" links that take your contacts to pages that contain the full article.
"Read more" links have an added benefit in addition to helping with truncated emails: these links are trackable so you can tell how many people clicked through and this can guide your content strategy. In contrast, it's not possible to tell how many people read a longer article contained entirely inside your email.
Media in emails doesn't affect email size by a lot
Images, videos and attachments don't significantly contribute to message size since emails themselves only contain a link to the files - the actual files are hosted elsewhere.
Use different subject lines to test messages in Gmail
Depending on recipients' settings, Gmail can display messages in threads that use the exact same subject line. Threads can grow long and this can result in messages being clipped. Changing the subject line when you're sending many test messages over and over prevents emails from shown in threads and instead each email is shown as a unique new message.
Related article: Troubleshooting email display issues