Let me try again (I first response wrong). The following may work:
#+latex_header: \input{preamble}
--
: Eric S Fraga, with org release_9.6.1-250-ge6353d in Emacs 30.0.50
- Use custom preamble from tex file for latex export reza
- Re: Use custom preamble from tex file for latex export Fraga, Eric
- Re: Use custom preamble from tex file for latex export Fraga, Eric
- Re: Use custom preamble from tex file for latex ex... reza
- Re: Use custom preamble from tex file for late... Fraga, Eric
- Re: Use custom preamble from tex file for ... reza
- Re: Use custom preamble from tex file... Ihor Radchenko
- Re: Use custom preamble from tex ... reza
- Re: Use custom preamble from ... Ihor Radchenko
- Re: Use custom preamble from tex file... Fraga, Eric
- Re: Use custom preamble from tex ... reza
- Re: Use custom preamble from ... Fraga, Eric
