[mr__y]

While email as a whole is indeed federated, email service for a single company is usually not, that is you have a single provider and when that provider happens to have technical issues your email might be down. While obviously you could use other provider (or even free email) almost immediately to send emails, you will not be able to receive/access emails that are sent to your primary address/domain until the provider resolves their issues.

[JD557]

>you will not be able to receive/access emails that are sent to your primary address/domain until the provider resolves their issues.

You won't be able to receive new e-mails, but if you use a local client like thunderbird, you can still access your old e-mails.

With slack down, I can only access the messages that I (luckily) have cached locally.

[jedberg]

Except that email has built in retries and feedback. Also it's expected to be async, so if a server is down for an hour, most people don't even notice.

[mr__y]

> email has built in retries and feedback

Yes it has and it is a great thing - hopefully no messages would be lost assuming that downtime is relatively short. This still does pose a (possibly minor) problem when some mails are urgent.