* Reliability of ones Internet connection should not be much of an issue, because SMTP servers should retry to deliver a mail for several hours/days. Otherwise a secondary MX could be used as a backup for mails in transit.
* Policies of ones ISP are often a problem for something like this, you likely need a "business connection" for something like this.
* Dynamic DNS could be used for receiving, but you won't have much success in sending mails unless you have reverse DNS working and that requires a static IP as far as i know. Most users will only get a static IP for "business connections".
* I'd be really interested how the combine their usage of GPG with multiple client. Is there some sort of key management included? How does it work with Webmail/Roundcube? Is the same key used for desktop and mobile phones?
* Policies of ones ISP are often a problem for something like this, you likely need a "business connection" for something like this.
* Dynamic DNS could be used for receiving, but you won't have much success in sending mails unless you have reverse DNS working and that requires a static IP as far as i know. Most users will only get a static IP for "business connections".
* I'd be really interested how the combine their usage of GPG with multiple client. Is there some sort of key management included? How does it work with Webmail/Roundcube? Is the same key used for desktop and mobile phones?