Whenever you need to step away from the office and won't be able to respond to emails as quickly as you usually do, it is good practice to create an out-of-office email autoresponder to guide your email correspondents on how to reach you, who else to contact, and/or what to do next.
Oh I also saw one from a person who used to be my manager (thank goodness that nightmare is over). She had: – An extra space in the email address to contact in her absence, which would create a bounce back if someone tried to use it as she typed it. – Had a date that was clearly a “fill in the blank” that she didn’t look at, because it was something like “3th” instead of “3rd.”

If that’s truly what you intend, great. But if not, you may want to take a deep breath and try this: “I am currently on vacation and not accepting emails. Please contact x for any issues while I’m away.” This approach is refreshingly honest and clear. And as long as you’re comfortable with the competence and availability of your back-up contact, you shouldn’t feel funny or guilty about going this route at all.
There is no solution work with this method. However, you can set voice message and send all unknown numbers to voice message, iPhone Settings > Phone > Silence unknown callers > Turn ON, See details here: https://mashtips.com/block-spam-calls-unknown-callers-iphone/