Don't reply to that passive-aggressive email, says communication expert: How to have a 'win-win conversation' instead

Receiving a passive-aggressive work email is annoying, and it creates a tough dilemma.

Do you muster the strength to ignore their tone and reply with a kind message? Should you match the sender's energy with a passive-aggressive response of your own? The best move might be not sending a reply at all, says executive coach and communication expert Susan Room.

Email, while efficient, isn't always the most effective way to communicate — especially if you have "negative feelings about the recipient," Room tells CNBC Make It.

And while it's normal to want to reciprocate any negativity sent your way, she says, remember: "It's not about winning an argument, but about maintaining a positive and productive working relationship."

Here are the most common passive-aggressive workplace emails, and Room's advice on how to handle them.

The 10 most passive-aggressive email phrases

Your first step: identifying the source of that passive-aggressive feeling. These 10 common email red flags are often a tip-off, according to a report last year from telecommunications provider TollFreeForwarding.com:

1. "Please advise"
2. "Kind regards"
3. "Friendly reminder"
4. "I look forward to hearing from you"
5. "Pay attention"
6. "Make sure"
7. "Per our conversation"
8. "Future reference"
9. "ccing"
10. "Going forward"

Other phrases that didn't make the top 10 but are still seen as condescending, according to the report: "I would like to follow up on my previous email" and "per my previous email."

How to have a 'win-win conversation'

Those phrases may raise your hackles, but it can be hard to decipher someone's tone through email. Follow up in-person or with a phone call, Room suggests.

"If you feel there's conflict, stop emailing, talk with people instead. And before you do, as well as preparing what you're going to say, plan how you will use the superpower that is your voice to say it," she wrote in a blog post last year, referencing the TollFreeForwarding.com report. "What blend of pitch, tone, pace, speed and volume will keep you working constructively together rather than reinforcing the battle lines?"

If a conversation is somehow impossible and you do need to write a follow-up email, be calm, clear and concise, says Room. Seek clarification when needed, instead of assuming the other person's intent, and speak only for yourself. Doing so will help you have a "win-win conversation," she says.

"Using 'I' statements when expressing your feelings can prevent the other person from becoming defensive," says Room. "For example, 'I noticed there was a misunderstanding in your last email about tasks assigned to me. Let's clarify the expectations to ensure a smooth workflow moving forward.' This approach not only addresses the issue but also sets a professional and respectful tone for future communications."

Lastly: These situations can be nerve-wracking, and if addressing passive aggression feels too far outside your comfort zone, Room says it's OK to just let it go.

"Ask yourself whether you need to respond at all," she says. "Sometimes, ignoring bad behavior is the best way of dealing with it."

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