In HSDS, when ZSF wrote letters to MJ of Emei:

Although E-Mei sect also had a portion of the 9 Yang, but Mi Jue Shi-Tai’s character was extremely strange. Zhang SanFeng had already written a few letters to her, asking Yin LiTing to deliver it to E-Mei, but Mi Jue didn’t even break open the envelope and would already send the letter back to Wu Dang, unopened.
What is the reason the author is trying to convey for MJ's actions?

Would it be reasonable to say she surmised what the letters were asking for and she felt this would be a better refusal than opening the letter and having to give a reason for the refusal? The problem i have with this reasoning is that there is not explicitly explained she had surmised the contents of the letter and she is also not one that would shrink away from a refusal.

Secondly, are we to just explain it away with the fact she is strange? I find this unsatisfactory since being strange is one thing but being so rude to another pillar of the martial arts world seems out of character for her, especially given the relationship between Wudang and Emei. Even when she was doing things which undermined their relationship she disguised it, eg. being the only sect to send proper gifts to ZSF when all of wulin pretended to congratulate him on his birthday.