Interesting question. I don't know if horary can show that, but my guess is it can. I know very little about horary, so I'm just speculating here...
The way you phrased your question sounds like you know that the bully is someone from work. Do you know that for sure, or only suspect? What makes you suspect it's someone at work?
I'm not sure which house should be used to indicate the bully. Enemies can be either the seventh house or the twelfth, depending on whether they're an open enemy (seventh) or a secret enemy (twelfth). If they're sending these emails to your husband anonymously, and you don't know who they are, that could make them twelfth house, in which case the bully would be signified by Saturn... but you do know that this person is bullying you, they're doing something to make themself known (emailing your husband), so seventh house might fit.
If we call this person a seventh house enemy, their significator is Mercury. Mercury is in the sixth house... I don't know if the sixth house is ever used to represent day-to-day work in horary, or if that's just natal astrology and the workplace would always be the tenth house in horary... but the "day to day work" meaning of sixth house is what springs to my mind when I see this. If that interpretation works, it suggests a coworker, for sure... someone who shares your workplace.
Mercury is domiciled, but it doesn't rule the house it's placed in. The sun rules the sixth house of this chart, and is also in the sixth. If this is a coworker we're talking about, I would guess it's someone who's very strong in the workplace, but not the boss--the boss would be indicated by the sun (it owns the sixth house). Maybe this is someone who has lots of responsibility, has been there for ages, and/or is considered the best at the job. Maybe they're a favorite in the workplace. In some sense, the workplace is their own home, even if they're just a tenant. Do you know anyone like that at work?
The other possibility, if we go with the twelfth house (hidden enemy), is that Saturn represents the bully. Saturn is in the ninth, which, to me, is more suggestive of someone you know through higher education than through work. How recently did you go through college/university? Is anyone you know from there still in your life, and could be emailing your husband? Or do you work in higher education? If you do, it could be someone from there.
Either way, your significator is Jupiter (late Pisces ascendant). I think Jupiter's placement speaks to your situation: in the house of open enemies, and also the house of marriage. Your husband (seventh house) is receiving these nasty emails... and we could also interpret this as you being surrounded by open enemies. But, this is Libra, so they're probably more like frenemies... people who are nice to you to your face, and act like your friends, might be nice and polite, but really dislike you.
Is your workplace full of people like that? That you think the email bully is someone from work makes me think that might be the situation.
If Mercury indicates your bully, you are in a house that they rule (DC in Virgo), but not the same sign. That suggests that you are in their home, in some sense, at work, but perhaps not the same department, perhaps a different area of work. There's no aspect between Jupiter and Mercury, so in some sense, you don't see this person. Don't interact with them much, perhaps.
If Saturn indicates the bully, it has an applying sextile with Jupiter. That suggests someone you do interact with. And Saturn is in a Jupiter-ruled house, so in some sense, they're in your home.
I know that horary significators can be used to get physical descriptions of people, but I don't know how to do it. Maybe someone else here does.