Dear Mohammed,
On 08/14/17 12:53, Mohammed Khalid Ansari wrote:
I have configured my postfix to run on 587. When I choose connection type as 'STARTTLS' everything is fine but when I choose 'SSL/TLS', the client throws error.
Normally, but deprecated, port 465 is used for “direct” SSL/TLS (without STARTTLS) [1]
465 – This port has been deprecated since RFC 2487, after being briefly assigned for secure SMTP in the 1990s. Despite this, it is commonly used by mail providers[20][21]
I can configure 'STARTTLS' in outlook and proceed but on my cell phone I don't have don't option and hence not able to connect.
That’s client dependent. Which client do you use. You should contact them. Kind regards, Paul [1] https://en.wikipedia.org/wiki/Simple_Mail_Transfer_Protocol
