Mail.app is using port 585 and blocking my server connection. How to block it?

EDIT SMTP SETTINGS

In Accounts window > Outgoing Mail Server SMTP: select to Edit SMTP Server list... from popup.

Select account in the list.(It's not uncommon to find extra SMTP servers listed. When you remove account, Mail does not delete the smtp info. You might need to do some clean up in the list to remove the extras.)

Under Advanced Tab:

Apple defaults to the default ports (25,465, 587) but some servers prefer a custom port.

Enter correct port number

Verify if your server require SSL.

User Name. Enter full email address eg. UserName@gmail.com

Add password if it is blank.(If you have two step authentication setup, you'll need to get an app specific password more info)

Open Connection Doctor under Window in the Menu bar.

Do you see green light now for your account SMTP?

Unfortunately, I haven't found the solution to this, either, and I find myself having to contact my mail host's tech support frequently to remove my IP from their blacklist.

I reset all of my SMTP settings and ensured that none of them use port 585 (I should note that none did when I started troubleshooting).

I read somewhere that Apple Notes syncs with port 585, so I disabled it with my non-Apple email accounts. I figured this was the culprit, as Notes has traditionally been buggy for me--it would create duplicates for every change I made in a note. I made all of these changes across all of my Macs and iOS devices...Still, no luck.

I'm also looking for an answer to block a port but os x firewall only allows application blocking.

I found some answers but they are written before Yosemite release and not working with it.

I just need to block a port and unblock it when I need to use it. I'm ok with Terminal solution but don't know what should I write.

Haven't verified this myself, but I thought I'd mention it in case it helps.

In the "Advanced" tab for the SMTP server settings there is an "Automatically detect and maintain account settings" checkbox. Try unchecking that - it may cause Mail to probe various alternative ports when it connects, to see if anything has changed.

There's a similar one for the POP3 / IMAP advanced settings tab as well, so uncheck that too.

"Automatically detect and maintain account settings"

The above is the correct setting which is located in 2 places (Mail -> Preferences -> Select Account -> Advanced) and also under the 'Advanced' tab in the SMTP settings, it's causing quite a lot of our clients to be blocked by our server when attempting to connect their Mac Mail service to our mail service. We don't operate port 585 (most hosting providers don't), so it's a little unusual for Yosemite to introduce this - is there a way to bring this to the attention of Yosemite developers?

We operate Linux based servers running cPanel and 1/2 of our time is spent on providing support for users with Mac Mail, we've literally grown to hate Mac Mail, it's such a buggy mail application overall.

xhash wrote:

We don't operate port 585 (most hosting providers don't), so it's a little unusual for Yosemite to introduce this - is there a way to bring this to the attention of Yosemite developers?

Yes — you can submit a bug report.

That's too bad that you have to sign up and become a developer.

You can register for free here: https://developer.apple.com/register/index.action. No need to buy a paid account.

Just been on to my provider about this and I couldn't find any SMTP on port 585 either. Try this:

Mail > Accounts > selct the account > Account Information > Outgoing Mail Server > Edit the SMTP list > Advanced

Go through all the accounts you have problems with and uncheck "Automatically detect and maintain account settings"

It's possible that the Automatically detect and maintain account settings option causes the application to make too many server requests. So I've just unchecked it on all my accounts to see what happens. It's happened to me twice in 3 days now, so I hope this fixes it. Will add a note here if it does.

Good luck.

Seems like it didn't, and I installed Little Snitch to try and find the culprit but had no joy yet. Unfortunately it does mean that my provider blocked me from all my client accounts meaning that I can't work while the block is in force. Given that this issue is all over the place and costing us all proper money an Apple tech should at least drop in here with some ideas. 😟

This is a community discussion list. If you want Apple support you need to contact Apple.

https://getsupport.apple.com/

What Port does your provider list for your account. Is it 465, 2525, 25???

Simply enter the correct port in SMTP.

Thank you. Yes I force all the port numbers - send and receive, I run about 25 mail addresses pop and IMAP for different clients but like I said in my last post - something is forcing a query to 585. It may not be mail. And the problem only started on installing Yosemite.

In the SMTP settings, simply enter the correct port. It default to 587 now but you can customize the port if 587 does not work.

Like I said I already forced the port numbers, and my provider recognises the issue. 585 seems unique to Yosemite looking for this port with something. The answer is not a 'simply' anything there's a rogue command being generated, just trying to isolate it but thanks for your input.