Replying works from day one. Writing to somebody who has never written to you first is a separate feature, and it has one restriction attached.

How to do it

The dashboard shows, for each alias, the address to write to when you want that alias to be the sender. It looks unusual on purpose, because it is read by our relay rather than by a person. Send to it from one of your verified recipient addresses, and the message leaves with your alias in the From header.

The recipient goes into the address itself, so you do not need a web interface to do it.

The thirty day rule

For its first thirty days, an account can reply but cannot write to somebody who has not written to it.

The reason is not suspicion of you. An account opened purely to send unsolicited mail is worth something only if it can send immediately, and the pattern is common enough that the large providers block whole domains over it. Our domains are shared by everybody here, so one such account costs every user their aliases.

The restriction lifts by itself. There is nothing to request and nothing to pay.

The first message from a new account

The very first outbound message from a new account is deferred once with a temporary error and accepted when the sending server tries again, which every real mail server does automatically within minutes. Software written to send once and vanish does not. You may notice a short delay, and nothing else.