Mail sent as preview allways trigger CheckLink.aspx

Steps to reproduce

Description:

When we use EPiServer Mail to send to a mailing list everything works fine. When the editors use the "send preview to a single email address" the genereted URLs does contain en empty RID-paramter, that forces CheckLink.aspx event.

We have disabled CheckLink using the [SkipLinkValidation="true"] directive in GoMail.aspx. Example URL from mailing list mail: (works)

See details for Link 1

Example URL from preview mail: (does not work)

See details for Link 2

If I manually alter the last link and insert something as the rid-value (...d0&rid=SOMETHING&url=https...) it works.

We have the same issue on both EPiServer CMS 7.1 and EPiServer CMS7.5

Steps to Reproduce:

Send mail from preview with a link. Click the link. Observe that you get the CheckLink.aspx-page instead of that page the link points to.