Then you just have a bunch of other worries; are your servers up and secure; not an open relay; has an anti-spam measure kicked in against your server so your emails aren't being read .... not saying you shouldn't do it, just that there are pluses and minuses to both.
Most of which is just paranoia and will never shoot you.
Are my servers up? Don't really care - SMTP will be redelivered if I discover they are down. They were down for about 2 days once thanks to the idiots at BT digging through the cable. No major effect other than some peace.
Is it an open relay? no it's not - I checked it.
Anti spam? I deal with it manually. I don't get much as I don't publicise my email address.
Fair point on SMTP retries, but "up" also includes "not under attack, not already hacked, fully patched & secure".
> Is it an open relay? no it's not - I checked it.
Good for you, you clearly have the skills to do so and to be confident in it. Not everyone does or even knows what that means.
> Anti spam?
Actually, I wasn't talking about the receiving spam problem. You can deal with that on your own server in many ways.
I was talking about the email you sent being marked as spam problem, so your intended receiver never reads it. Maybe your reverse DNS records are wrong or missing, or SPF records, or one of a thousand little things. This is much harder to fix, as you have to do it on each mail host you send to, and worse, you may not even realise it's happening.
Again, not saying you or anyone shouldn't, just that there are downsides that need to be considered. I did it for years then realised my time was better spent elsewhere and moved to Google Apps.
You'll never have to worry about getting kicked off or them going under then.
I've been running my own mail server for 15 years and I've probably spent a couple of hours administering it over that time.