Apple Mail 7.1 (1827) Slow to Send Mail Messages

Question

Apple Mail 7.1 delays the sending of messages from iCloud or third-party ISP mail accounts by 20 to 30 seconds. While this behavior is not 100% consistent, it is reproducible 70% of the time.
Restarts or quit & relaunch Mail.app has no impact. Apple Mail has had all night to sync my two accounts (1 iCloud account and 1 third-party ISP account)
No error messages are thrown, all mail does send successfully, eventually.
This problem occurs on both my Apple MacBook Pro 2.7 i7 mid– 2012 and 2.6 Mid-2012. One had a fresh copy of Mavericks installed and the other had an update from Mountain Lion.
Synchronization has been performed, as well, the rebuild command has been executed.
The behavior also occured during an attempt to investigate the issue when a Mail account (in this case, a friends iCloud account) was installed into a newly created computer user account (standard or admin)
Clearly, not the most serious problem to have but one that merits discussion and eventual resolution.

Answer 1

I am having the same issue with Mail 7.1 (1827).  I have looked at all of the alternatives, but keep coming back to Mail.  Airmail Beta, however, was outstanding.  Write an email click send and it's gone like a rocket!  If they keep developing, they will give Mail a run for the money.
That said, I like the search abilities in Mail and the smart folders.  I keep coming back.  Plus I like CMD+Shift+D to send.  If I am out at a wifi spot and do an email, I really don't like having to sit there waiting for Mail to decide wether it wants to send or no.  Perhaps I'll look at using alternative smtp ports?  Maybe Mail doesn't like using port 26? Whatever the case, I wish they'd fix it.