Mail.app not working. Need to backup before reinstalling.

What have you done to try and fix the problem? Do you know that you will have to reinstall all of OS X? Buy a suitable drive to use as a backup drive. Then use a good backup utility to make the backup.

Backup Software

Using Time Machine is very easy, and all the tools you need come with OS X. If you later need help with Time Machine then I highly recommend a visit to Pondini's Time Machine FAQ for help with Time Machine. This is an extensive site with most everything you may need for using Time Machine. You will not find a better resource for Time Machine of OS X in one location. Due to the passing of James Pondini the site is no longer being updated. Therefore, some of the information may be outdated.

As an alternative, you can use any third-party backup utility your prefer. They all create straight file backups meaning you can restore individual files manually if you want by drag and drop copy.

Recommended Backup Software

1. Carbon Copy Cloner
2. Get Backup
3. Deja Vu
4. SuperDuper!

Visit The XLab FAQs and read the FAQ on backup and restore. Also, read How to Back Up and Restore Your Files.

Some similar threads for alternative backups:

• Need solution for Mac Mail backup..!!
• https://macosx.com/threads/how-can-i-automatically-backup-apple-mail-email-datab ase-on-my-hard-drive.323922/

Reinstalling the mail application is not possible as it is already inbuilt in Mac .

If you want to know the method how to back up of all email folders that you created in the mail side bar , please insert a USB stick ( may be of size 32 GB ) open user library macOS Sierra: Library folder

And select mail and right click on it , click on copy mail

Open USB stick by double clicking on the image of USB stick that is formed on the desktop .

Take cursor on pen drive shown with red arrow , right click on pen drive and click on paste items .

All mails will start copying and you will see a bar is loading stating copying mails ( no of items and some time will be shown ) .Once it is completed you can again open USB stick all mail data , including your mail folders will be saved in the V4 folder , but only V4 folder ( that is a mother folder ) will be shown and not your inbox , sent , items or new mail box folders that you have created .

Right click on USB stick and eject .

Note : V4 Folder is in Mac OS Sierra , V3 , V2 is in Mac OSX EL- Capitan and Mac OSX Yosemite respectively .

And about , how to save contacts an article Contacts for Mac: Export and archive contacts

Hi,

"I wanted to know how can I backup the email folders and contact lists as well if I am going to reinstall the mail.app application?"

"No matter what I do it crashes every time I try to open it."

There is no way to just reinstall the Mail app without restoring OS X. You shouldn't lose your email just by restoring OS X. If you were to restore to factory settings, that might delete your mail but you don't need to do that.

Startup your Mac while holding down the Command + R keys.

From there you can restore your Mac using macOS Recovery.

Not knowing anything of your accounts, you can backup your Mail folder to another external drive such as a flash drive. Go to ~/Library/

Copy the Mail folder to another location, preferably an external drive for a backup.

Then follow procedures below:

Remove Container file Mail:

Quit Mail.

In the Finder, select Go, then Go to Folder. Copy and paste the path below and hit GO:

~/Library/Containers/com.apple.mail

Move the whole com.apple.mail folder to the Trash, and open Mail and test. If all goes well, you can empty the trash. You may need to re create your user settings.

If there is a problem or you wish to restore the old file, first, Quit Mail.

Then open the Trash. Right click on the folder and choose Put Back from the menu.