各位好,近一個禮拜公司mail無法發信至GMAIL信箱,退信內容如下:
host gmail-smtp-in.l.google.com[142.250.157.26] said: 550-5.7.25 [xxx.xx.xx.xx] The IP address sending this message does not have a 550-5.7.25 PTR record setup, or the corresponding forward DNS entry does not 550-5.7.25 match the sending IP. As a policy, Gmail does not accept messages 550-5.7.25 from IPs with missing PTR records.
但查詢PTR,是有被設定上去的,請問還有什麼地方有狀況或是沒設定到,導致無法發信至GMail信箱嗎??
FQDN->IP(正解)和IP->FQDN(反解)是兩回事,因為現在一般user很難拿到一整個Class C,所以反解通常是在ISP那一層做掉的,要設反解就得叫ISP處理,在自家的DNS上設基本上是沒有作用的....