Using custom fonts in HTML signature

We use IceWarp web client for our corporate mail. Lately a new, standarized e-mail signature has been designed. I'm trying to implement it. As the signature editor may be switched to raw HTML mode, it is not difficult, except of one thing. The signature uses custom font selected from Google Fonts service.

Google Fonts offers two ways of using the font: via <style> tag or <link> tag. Unfortunately postprocessing of signature code done by IceWarp creates problem:

• <style> is moved to the end of signature, so becomes ineffective.
• <link> is removed completely.

Is there any other way to use external font in the signature?