E-mails are two-way conversations in most cases. Aren’t there any privacy issues for the other parties to these communications? Don’t they have standing to sue whoever approved the release of them?
Most times when you contact a public servant you have to do so by way of their website. The websites make it abundantly clear that such communication is considered to be public and subject to FOIA requests, law suits, etc. The ones I’ve seen go out of their way to make sure the writer can not expect, or be given, any promise of privacy.