The service name smtp.johnshopkins.edu is the official outgoing email gateway for the Johns Hopkins University and the Johns Hopkins Medical Institutions.  This service name supports Transport Layer Security (TLS) or email client/server encryption, SMTP authentication, anti-virus, anti-spam, and JHU and JHMI alias routing.  The following information will help you configure your email or application server to use smtp.johnshopkins.edu:

• Make sure that the IP address that the server will be using is registered in DNS.  It is important that the IP address have a reverse lookup or PTR record.  To check to see if your IP address has a reverse lookup and that it is working correctly, perform the following "nslookup" (network tool available on most OS platforms):

# nslookup

Default Server: jhname.hcf.jhu.edu

Address: 128.220.2.7

> 'server 128.220.2.7' or 'server 162.129.20.10'

Default Server: jhname.hcf.jhu.edu

Address: 128.220.2.7

> 'Your IP address here'

Default Server: jhname.hcf.jhu.edu

Address: 128.220.2.7

Name: "Your hostname should appear here"

Address: "Your IP address should show here"

> exit

If you receive an error similar to "*** jhname.hcf.jhu.edu can't find "Your IP address": Non-existent host/domain", then your IP address does not have a reverse lookup set up.  Please email <hostmaster AT jhu DOT edu> and request a PTR record for your IP address.  Don't forget to include the hostname that the IP address should reverse lookup to.

• It is not necessary to configure your email or application server to use SMTP authentication.  In fact it doesn't really make sense because SMTP authentication is used to authenticate users and not servers.  You would need to use a valid JHED LID and JHED password and it would not be recommended to use your credentials to authenticate an email or application server.
• You can configure your email or application server to use TLS to communicate with smtp.johnshopkins.edu if you wish to secure the communication between these two servers.