SMTP seems to be the protocol for transferring emails through one messaging service toward the next.
HELO seems to be an SMTP command transmitted by someone with an email server that recognizes yourself when you communicate to some other email server to begin the mail transmitting procedure. It is accompanied either by a domain name including its email address that is sent.
Simple Mail Transfer Protocol (SMTP) is a protocol followed while sending an electronic mail or receiving it. It is a TCP/IP protocol (a protocol used to interconnect in communication protocols).
<u>To test Simple Mail Transfer Protocol (SMTP), the HELO/EHLO command is used</u>. There are several other commands in SMTP, which is used to communicate properly.
The HELO command is a type of command in SMTP which is used to test or initiate SMTP communication. HELO/EHLO are the commands which are used to test SMTP communication. <u>They are used interchangebaly</u>.
Thus the correct answer is HELO/EHLO command is used to test SMTP support.
