Exeption: Cannot read property '_syncSendMail' when no mail server is defined

Description:

After upgrading to rocket chat 4.7.0 we are getting these errors in our application that is integrated using the rocket chat API so this is a regression.

This issue seems to be related to this:
https://github.com/meteor/meteor/issues/11709

Steps to reproduce:

1. Make sure there is on mail server defined in the configuration.
2. Update the email address of a user.

Expected behavior:

No attempt to send an email should be made and no error message should be displayed.

Actual behavior:

The following error is reported:

Exception in defer callback: TypeError: Cannot read property '_syncSendMail' of null
    at smtpSend (packages/email/email.js:154:13)
    at Object.Email.send (packages/email/email.js:233:5)
    at app/mailer/server/api.ts:176:27
    at Meteor.EnvironmentVariable.EVp.withValue (packages/meteor.js:1257:12)
    at packages/meteor.js:555:25
    at runWithEnvironment (packages/meteor.js:1320:24)

Server Setup Information:

• Version of Rocket.Chat Server: 4.7.0
• Operating System: Docker
• Deployment Method: rocketchat/rocket.chat:4.7.0
• Number of Running Instances: 1
• DB Replicaset Oplog: NA
• NodeJS Version: NA
• MongoDB Version: 5

Client Setup Information

• Desktop App or Browser Version: Browser Chrome 101
• Operating System: Linux

Relevant logs:

Exception in defer callback: TypeError: Cannot read property '_syncSendMail' of null
at smtpSend (packages/email/email.js:154:13)
at Object.Email.send (packages/email/email.js:233:5)
at app/mailer/server/api.ts:176:27
at Meteor.EnvironmentVariable.EVp.withValue (packages/meteor.js:1257:12)
at packages/meteor.js:555:25
at runWithEnvironment (packages/meteor.js:1320:24)

Start in app/mailer/server/api.ts at the Email.send call around line 176, then inspect packages/email/email.js where smtpSend fails. Reproduce with no mail server configured and a user email update; done means the update makes no email attempt and reports no error.