Need to write an important email? If you can, avoid composing it on a Monday—but if it can’t wait, make sure to double-check the subject line’s spelling, grammar, and punctuation before hitting the "send" button. As Business Insider reports, a new analysis conducted by email productivity tool Boomerang found that online missives sent on Mondays are more likely to contain subject line errors than digital dispatches crafted on other days of the week. In turn, these emails are less likely to receive a response from recipients.

Boomerang used automated grammar-checking software to scan the subject lines of more than 250,000 emails and monitored their response rate. Not surprisingly, they discovered that Monday—the day we’re settling back into business mode after a weekend away from the office—is when people make the most mistakes.

Stray typos might not seem like a big deal (unless you’re a die-hard grammarian), but Boomerang's data scientists discovered that they affected reply rate. Mistake-free subject lines had a 34 percent response rate, but emails containing one or more typos in the subject line—think improperly capitalized words, spelling errors, and faulty punctuation—had a response rate of only 29 percent. The more errors there were, the less likely the email was to receive a reply.

Even minor mistakes mattered: Email subject lines with a lowercased subject line received a response around 28 percent of the time, but when senders utilized proper capitalization, the number jumped up to nearly 33 percent.

If you’re notorious among your colleagues for your poor composition skills, take some consolation in the fact that Boomerang’s findings likely carry more weight for cold emails than routine correspondence.

"If you get an email whose subject line is riddled with mistakes, you might assume it is spam and not open it, let alone respond," Brendan Greenley, Boomerang's data scientist, told Business Insider. "We expect that mistakes have a bigger effect on whether someone reads or responds to a cold email compared to emails from friends and colleagues."

Typos weren't the only thing wrong with Monday emails: They also contained subject lines with the most negative sentiments, and "moderately positive and moderately negative emails get more responses than neutral emails or those with extreme positivity or negativity," Greenley told BI.

Since the average office worker sends and receives around 120 emails per day, it’s hard to dodge important correspondence at any given moment, let alone Mondays. So if your first work day of the week does involve a big-deal email, just remember to keep your tone upbeat (even if you’re not feeling it), and scan it for errors before you send it off. And if it's possible, plan ahead: Write emails ahead of time—ideally over the weekend, when our typo frequency is at its lowest, and our moods at their highest—and schedule them to go out Monday morning.

[h/t Business Insider]