Below is the content of an smtp log file for a test message. As you can see, there is a delay of 14 seconds at the start, during which nothing seems to happen. I emphasise again that this didn't happen with v.3.95.
[21:07:57] C: Connected to mail.btinternet.com, port 25
[21:07:57] S: 220 smtp811.mail.ird.yahoo.com ESMTP
[21:08:11] C: EHLO brian
[21:08:11] S: 250-smtp811.mail.ird.yahoo.com
[21:08:11] S: 250-AUTH LOGIN PLAIN XYMCOOKIE
[21:08:11] S: 250-PIPELINING
[21:08:11] S: 250 8BITMIME
[21:08:11] C: AUTH PLAIN
[21:08:11] S: 334 ok, go on
[21:08:11] C: AGJyaV9tb3JyaXNvbgB2ZWRhZGkzMA==
[21:08:11] S: 235 ok, go ahead (#2.0.0)
[21:08:11] C: MAIL FROM:<my e-mail address>
[21:08:11] S: 250 ok
[21:08:11] C: RCPT TO:<my e-mail address>
[21:08:11] S: 250 ok
[21:08:11] C: DATA
[21:08:11] S: 354 go ahead
[21:08:11] C: Date: Mon, 12 Mar 2007 21:07:51 +0000
[21:08:11] C: From: <my e-mail address>
[21:08:11] C: X-Mailer: The Bat! (v3.98.4) Home
[21:08:11] C: Reply-To: <my e-mail address>
[21:08:11] C: X-Priority: 3 (Normal)
[21:08:11] C: Message-ID: <54756440.20070312210751@my e-mail address>
[21:08:11] C: To: my e-mail address
[21:08:11] C: Subject: Test
[21:08:11] C: MIME-Version: 1.0
[21:08:11] C: Content-Type: text/plain; charset=us-ascii
[21:08:11] C: Content-Transfer-Encoding: 7bit
[21:08:11] C:
[21:08:11] C: Message text
[21:08:11] C:
[21:08:11] C:
[21:08:11] C: .
[21:08:11] C: {463 bytes sent}
[21:08:11] S: 250 ok 1173733691 qp 32607
[21:08:11] C: RSET
[21:08:11] S: 250 flushed
[21:08:11] C: QUIT
[21:08:11] S: 221 smtp811.mail.ird.yahoo.com