Replying to a business email

[WilyWindyMoors]

How long is too long? And would you apologise for delay?

Email from someone v senior to me in organisation but not urgent

One of my mid-management colleagues has found an incredibly efficient method of dealing with mailbox overflow during an absence:

His ooo reads that he's absent and messages won't be read. Please contact other guy or email him again after return date. He also has an Outlook Rule that simply bins messages except those from specified senders considered important.

I dare not do it myself but have to say it works exceptionally well for him. He's the only person I know who doesn't spend his first two days after a holiday sorting through thousands of irrelevant messages.

I'm self employed so never use OOO
but I'm in the habit of logging in once a day (even on holiday)

some messages sit for a while before I respond - I've trained pretty much everybody to not panic till a week has gone past.

In Op's case I'd say

While on my sabbatical I've not been responding to email every day, however my considered response is ....

When on holiday I often send "holding" messages to give me time to think.

Is your out of office on? If yes, no apology. If query not urgent, no apology, if no ooo and urgent query, a simple apologies for the delay in getting back to you...