Letter of recommendation issue: through Naviance, but teacher no longer at school

[Anonymous]

My son is applying as an engineering major to X university. When we toured last fall, the person who gave the admissions talk was very clear that although it says "optional" on the webpage, since Engineering is very competitive students applying NEED to submit two letters of recommendation and they must be from academic teachers (no sports coaches, bosses, etc.)
My son had an excellent relationship with his math teacher and another teacher (Engineering) that he asked for letters of recommendation last spring and they agreed.
The only problem is, the math teacher no longer teaches in this district, he moved to teach in another county. He told my son about this when my son asked last spring, and gave my son his email address so my son could contact him about the letter. My kid's school does the letters of recommendation through Naviance (do all schools now?) and since he no longer teaches in the district, the math teacher can no longer submit a letter as a teacher. Apparently there IS a way for him to submit the letter as "other letter of recommendation" but given that we were specifically told that the recommendations must be from teachers, I'm concerned that the university will just see it filed as "other" and not bother to read it and see that it actually is from a teacher.

My son could ask his history teacher for a recommendation, but I wasn't sure if a history teacher's recommendation carries as much weight for someone applying to engineering...and will the university wonder why/think it's a red flag that there is no math teacher recommendation?
Should my son contact X university and explain the situation and maybe there can be some type of note/flag on the file that the "other" recommendation IS a teacher recommendation? It's a HUGE school so I'm sure they are receiving thousands and thousands of applications.
Another thought I had--have the math teacher write the recommendation and submit as "other" but ALSO ask the history teacher to write the letter (and engineering teacher) so my son will have 3 total recommendations?
FWIW, his English teacher also moved to another district, so same situation as math teacher. I asked if he wanted to ask his science teacher from last year, but he thinks it's better to ask his history teacher.
Am I overlooking any better solutions?

Back in my day the teachers actually wrote an email on paper and sealed the envelope (and signed across the seal) and handed it to me, then I handed the envelopes to my guidance counselor. Now everything is done through portals.

[Anonymous]

Check in the other section of the recommendation section - you have to pick what kind of "other" they are - and I believe you can say teacher as one of the choices.

[Anonymous]

Anonymous wrote:Check in the other section of the recommendation section - you have to pick what kind of "other" they are - and I believe you can say teacher as one of the choices.

Oh really? Thank you so much! I didn't realize that!