How to hide my private IP in Email header in Thunderbird?

It seems Thunderbird sends out my private/lan IP to the SMTP server. For example, in an Email sent out by Thunderbird, the header contains Received: from [] ( []) by (Postfix) with ESMTPSA id 92CD297DEA; It is fine that the SMTP server records the public IP ( as it is what it sees. But […]

Max number of Emails allowed to Sent from Gmail SMTP per day

Gmail’s SMTP is convenient. You “sender” needs not to be always your Gmail address (but the emails will include your Gmail address in the header “send by”). I am wondering how many emails at maximum can I send each day through Gmail’s SMTP. Here there a nice recent list of the sending limits of the […]

Sending Email Using mailx in Linux Through Internal SMTP

How to Send Email from mailx Command in Linux Using Gmail’s SMTP introduces how to send email using mailx or mail command in Linux through Gmail’s SMTP which requires some configuration. On the other hand, there are many environments that do not require SSL/TLS/etc. One example is the SMTP server ( for HKUST requires no […]