This is related to the User Relationship Invites module.

When an invitation has not been accepted for 30 days, it is listed as Expired. An option given is to Resend the invitation.

The email that is generated contains the text & links twice.

The mail template is set to:

From: ABC LLC

We invite you to learn more about ABC.

[invite:invite-message]

To get started, click the link below or paste it into the address bar of your browser.
  [invite:join-link]

Best regards,
  [current-user:name]

The email sent by the Resend function is:

From: ABC LLC

We invite you to learn more about ABC.

From: ABC LLC

We invite you to learn more about ABC.

To get started, click the link below or paste it into the address bar of your
browser.
   http:// abc .com/invite/accept/<em>UniqueCode</em>

Best regards,
   admin

To get started, click the link below or paste it into the address bar of your
browser.
   http:// www.abc .com/invite/accept/<em>UniqueCode</em>

Best regards,
   admin