I'm not a Quic employee or customer, but I do have a lot of experience with mail servers.  My 2cents worth is below.

Technically yes you can, but I strongly advise against it.  The IP address range that your static IP address will be a part of will likely have a low level of trust as far as spam filters are concerned, resulting in a higher likelihood that your sent messages never reach their destination.  If you set up PTR, SPF, DKIM and DMARC for your mail server you may have good success if you are patient and don't mind doing troubleshooting while some of your emails are being blocked by the receiving email server.  It might be a fun challenge and a great learning experience.  I would not even attempt it for an email address important for business as the benefit of the change is almost certainly outweighed by the risk of missing business-critical communication.

Dynamic:

 

 The IP address range that your static IP address will be a part of will likely have a low level of trust as far as spam filters are concerned, resulting in a higher likelihood that your sent messages never reach their destination.

 

On the other hand, if you're using a cheap VPS, chances are your delivery will be better as many of those providers have absolutely terrible IP reputations despite efforts to keep on top of malicious use.

There is also no reason you can't split inbound and outbound e-mail or relay via a smart host from your own seever. If you're sending 20 e-mails per day, you can sign up with SMTP2Go and just use their free plan, which allows you to send 1,000 e-mails per month. Let them worry about the IP reputation for outbound e-mail.

I ran my own mail server for a few years, was a learning experience, but a pain in the *** when something went wrong.

Hi.

Thanks for your comments/suggestions. I'm fully aware of the perils of self-hosted email, and with issues with low-cost VPS IP's being on ban-lists, especially Hotmail/Outlook. I use big-name provider email address for business, TradeMe, Geekzone etc so that's not so much an issue. 

I have looked in to STMP relaying a little & will check out the suggestion thanks. I mostly need some confirmation that it will actually work with the static IP?

Ta

@Plx If you ensure you've got SPF, DKIM and DMARC set up on your domain then you shouldn't run into too many problems. Quic does offer self service RDNS (https://www.geekzone.co.nz/forums.asp?forumid=194&topicid=310519) - a good test is to send an email off to somebody on an outlook.com email as Microsoft seems to be the most picky.

I've got a friend of mine who uses Mailcow to achieve a secure mail server: https://docs.mailcow.email/#what-is-mailcow-dockerized

Relaying via smtp2go could be an idea for you too but give your own IP a go first ensuring you've got RDNS set (eg - mail.yourdomain.com). There is the other side of this and that is ensuring that your server is perhaps on another VLAN separated from your own network just in case there is a vulnerability in any of the packages it is running.

I run a family mailserver (Zimbra, but soon transitioning to Group-Office, protected behind a Proxmox Mail Gateway).

You will likely run into spam issues as your hosts' reputation with other mail systems "warms up", and you'll have to go through some validation processes with some mail providers or their filtering providers (such as Abusix for SMX). Definitely start with a test or low-impact domain or subdomain first. 

You also have to be very careful to make sure your mailserver is secured from abuse - test and test again to make sure you've not accidentally misconfigured it to be an open relay, and that there's security protections in place to protect against any accounts on it being hijacked. I use a combination of geofiltering for access and MFA for authentication, plus fail2ban.

On the side I can see that my PMG (Spamassassin-based) mail filter is not liking Quic's status updates today, and it's the TLD for vetta.online that's upsetting it - this shows how hard it can be to get things right!