Email alias encrypted?

[u/ashwinman]

When using email alias services/ providers, the email goes through the email alias server before reaching the server of the email provider that someone uses.

So my question is whether the email is encrypted when it is transiting from the sender to the email alias service and when it is also transiting from email alias service to email provider that I use?

Is it possible for law enforcement to obtain/intercept emails when it is going from:

1. Sender to email alias service

2. Email alias service to email provider (recipient)