On Fri, Nov 28, 2008 at 11:30 PM, happymaster23 <happymaster23 at gmail.com> wrote: > Hi, > > I have Sendmail configured to use STARTTLS for authentication. On all > internet connections and computers (that I have tested) works > connection over encrypted SMTP flawlessly. Today I was setting up mail > client on PC of my customer and standardily checked boxes, that I want > to use SSL for POP3 and SMTP. Next I wanted to check configuration (by > sending email from this mailbox to this mailbox) but it does not work. > > So I have opened telnet, connected via port 25 and writed "ehlo > hostname" and then finded out, that there is missing STARTTLS. Is > possible, that some bad configuration on client side (firewall, > etc...) can cause this error including that this function is missing > in printout of ehlo? POP3S working good. > Hi, I have seen this kind of problem (STARTTLS not available for a single client but working for everyone else) when the client is behind a CISCO firewall with the FIXUP SMTP configuration option enabled. Disable it using "no fixup protocol smtp 25" on the firewall and try again. Regards, Radu