how do I reset my apple email password but not my apple id password?

As you are using a non-Apple app to access your email, you are now required to use an 'app-specific' password in place of your normal iCloud password. In order to do this you need to set up two-factor authentication for your Apple ID, and for this you need to have either a Mac running El Capitan or above, or an iOS device running iOS9 or above.

Two-factor authentication for Apple ID - Apple Support

Using app-specific passwords - Apple Support

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If you are unable to set up two-factor authentication you should set up 2-step verification and use that to create an app-specific password (see link below) . Then go to https://appleid.apple.com , select 'Password and Security'; click 'Generate an App-Specific Password' and follow the instructions. Once you have the password, copy it and paste it into the password field in the application instead of your usual iCloud password. You should also keep a note of it (though you can generate a new one if required).

Two-step verification for Apple ID - Apple Support

You will need to nominate a 'trusted device' - any phone capable of receiving SMS messages. There will be a 2-day wait before you can complete the process.

(A particular caveat (about 2-step only) - you will be issued with a 'Recovery Key' in case you lose your 'trusted device'. Make sure to write this down and keep it in a safe place; if you lose both it and your trusted device you will be permanently locked out of your ID. You'd be surprised at the number of people who've posted here that they've got themselves into just that position.)

It sounds like these are two different Apple IDs. Your iCloud email address is a also and Apple ID and the password reset process is the same.

https://support.apple.com/en-us/HT201487

You have signed with your only Apple ID address say example1@gmail.com in Mac system preferences > iCloud .

Open a new tab ( use command and T keys ) and open www.icloud.com click don't fill up the password and click on use a different Apple ID .

Click on forgot Apple ID or password .

If the account is set up with two factor authentication enter the trusted number and click on continue .

Click on show notifications that appears on the top right corner of the screen , System preferences opens automatically , click on reset password and follow the up coming instructions .

The other way is click on using your device is the easiest and safest way ....on the right side of the screen shot .

If you click on don't access to have this Mac , the above screen shot will appear , you can reset the password , if the account was set up with secondary authentication in which three answers and questions , date of birth , rescue mail address and password is set , the article LAC Allen has posted will work .

Please mention which Mac version are you using .

Have you set up an app specific password?

Outlook needs this to access the Apple server