emails disappear from MacBook.

Hello BabsMidwest 196,

Welcome to the Apple Support Communities. I understand some older emails are not appearing. You've reached the right place for help.

Here are some suggestions that can help depending on the type of email account this is:

• If you use iCloud for your email service, check the iCloud website to see if the older messages still appear there: iCloud
• If you use a different mail service, like Google or Yahoo, check their webmail directly to see if the messages appear there. If they don't, reach out to your Email Service Provider directly for assistance.

Thanks and have a great day.

You are welcome.

Try rebuilding the mailbox by selecting it and then going to Mail/Mailbox/Rebuild.

If that doesn't work, try re-indexing the mailboxes. This can take awhile if you have a lot of mail.

Reindex messages         For El Capitan, try looking in V3.  Sierra use V4. High Sierra use V5.

Reindex messages (2)        See post by Linc Davis