I'm looking for a mail client that supports delaying sending of individual messages until a certain time and date.
The use case here is to write a work email on Saturday, and have it sent on Monday morning. The simplest implementation would be to that every mail gets saved in the Outbox with a scheduled time/date, and every time I click the send/receive mail button, scheduled messages are sent only if they are past the scheduled date. So for example if I schedule a message to be sent on 9:00 AM, but only actually launch my mail client at 10:13 AM, it would be sent at 10:13. Even if I send/receive other mail at 8:59 AM, the scheduled mail would not be sent.
Besides this, I also need the following features:
- Runs on Linux
- GUI preferred
- Supports IMAP
- Supports multiple accounts
The only solutions I know are Thunderbird with addons and using online services that MITM your outgoing mail. I don't know of any client that supports this natively.