The following issue affects links of type external and mail. The behaviour seems correct for attachment and explorer links.

How to reproduce

• Insert a link (external or mail) in a rich text.
• Insert another link after the previous one.
  --> A graphical issue will appear on the first link (icon is misplaced etc...)
• Save
  --> The data of the first mail is corrupted.

I am pretty sure that the graphical issue and the data loss have a common root cause.

By playing with link insertion and save/edit operation you can arrive in a state where every links are corrupted.