Have you told Apple?
Telling us users isn't very useful as we have no way of fixing Mail.
Of course, the majority of us have no problem with Mail, sending, receiving, or just sitting idle.
If every email seems to take a while to send, my first guess would be a DNS issue. Some routers don't do a good job of passing the information back which tells the computer which ip address to use for a given named address.
But, that is only a guess at this point.
I send many mails to apple with no answer.
Anyway, when I configure another mail tool like Thunderbird or Opera or outlook on the same computer using the sane wifi using the same router, unsing the same IMAP and SMTP config, all is working fast.
Is a DNS can cause trouble to a specific product ? not an expert.
Also, if I use an Ipad all is OK.
This trouble happend suddently 3-4 month ago, I have upgraded today to Mountain lion, but the problem still there.
But, hoping I'm wrong, I really think that is a problem with MAIL apple app. and the communication with their outgoing mail server.
DNS is domain name server. It converts smtp.whatevercompany.com to 188.8.131.52, which the computer needs to connect to the server. If you are not getting delays in other internet services, it is not the DNS.
Apple doesn't answer emails, nor do they respond to feedback. And, they don't hang out here, either. If you want to report a bug, create a free Apple Developer account and use the bug reporter.
I'm not aware of any problems with Mail and iCloud as mine works flawlessly. It could be something with your particular setup.
What third-party software do you have installed the might interfer with the system?
Hum...I don't remember if my problem begins with new software installation. I've check CPU usage during sending e-mail, and nothing special. The CPU still almost sleeping.
But when I open the activity window in MAIL app, I see that the communication with SMTP server seem very long.
With Thundernird is less than a second but in MAIL it's around 30 sec.
If it is iCloud, only, try going to the iCloud system pref and uncheck Mail. It will warn that you will not have access to your iCloud email.
Then, open Mail, Preferences, Accounts and select any account. Go to the Account Information tab and select "Edit SMTP sever list" from the outgoing mail server pop up.
If you see any iCloud related servers in the list, select them and delete them.
Then, go back to iCloud check Mail again to get it to resetup the iCloud email account. See if that helps.
Hi I have been having the same issue, ever since iCloud came in. sending is very slow, and sometimes doesn't happen at all, although receiving is fine. No problems before iCloud.
It has been worse the past week.