Lotus Domino 點用 STARTTLS ?
最近不在香港,不過呢 .... 有客投訴話e-mail 寄唔返去大陸 ,原來大陸最近好多server 已經預設要STARTTLS , 咁點搞好

1. 乜係STARTTLS :
一般SSL ,都要另外比個port 佢,但係E-mail (SMTP) 有點煩,好多時都係只用port 25 , 咁點好,如果雙方都支援START TLS , 可以雙方溝通後,用TLS 送出E-mail , 這樣可以一個 port 25 做晒,唔駛再開新port
inbound STARTTLS (對方要用STARTTLS 寄信給我方)
打開configuration document
Router / SMTP -> ADvanced -> Commands and Extensions
係SSL negotiated over TCP/IP Port , 按enabled

outbound STARTTLS (寄信出去時,對方要用STARTTLS, 即係問題所在 .... )
打開Server document
ports -> internet ports -> Mail
係mail (SMTP outbound) , 係enforce server access settings , 按negotiated SSL (預設是enabled)

再restart router 及SMTP task
remark 1: 要有SSL cert , 整SSL E-cert (記住係整係你client side , 再抄返上server): http://www-01.ibm.com/support/docview.wss?uid=swg21114148
remark 2: STARTTLS 做乜 ? 緊係唔想中間有人睇到你send 緊乜啦, 只需要用25 port , 唔駛再開port , 點解要咁秘密 ? 做開大陸生意,你會懂的.... 係個件野拖慢左個速度,仲有時會成個停左, 信都收唔到,所以好多大陸e-mail server 轉用STARTTLS 囉 ... 睇都唔比你睇 ...
remark 3: 呢個文章係幾好的解釋 : https://www.fastmail.fm/help/technical/ssltlsstarttls.html