When talking to people on the phone for the first time, is it correct to use "This is" and "I am" together

Question

A scretary told me to leave a voice message to her boss, because he was busy at the moment when I dialed his office number.
So, I left him a message like:

Good morning, Mr.XYZ. This is Kitty Lastname. Kitty Lastname is my real name. I am not a machine. I am from the ABC cake shop, which is located a few miles away from your company. I tried to keep in touch with you but your secretary told me that you were very busy. Sir, you had left your XXX under the chair you were sitting...

My teachers used to tell us never use "I am" on any phone call conversations, so I am very not sure whether I was wrong to say "this is" and then "I am" together in the above voice message.

Please help me.

Answer 1

Your teacher probably meant that native speakers do not usually answer the questions:

Who's this? or

With whom am I speaking?/Who am I speaking with?

on the phone by saying I am (name). Instead, a native speaker would usually say This is (name) when first identifying oneself.

And this is what Kitty does, in your example.

And, after first saying This is Kitty, it is absolutely correct to provide additional information about oneself by using I am... So your example is correct on this usage also.

Answer 2

This is Kitty. I am the manager of XYZ cake shop.

and

This is Kitty, the manager of XYZ cake shop.

are equivalent, and perfectly acceptable English usage over the phone (and in person, in written correspondence, etc.). While a 40 year veteran diplomat might be more formal, 99.9% of the English speaking world consider this a perfectly acceptable way to get to the point politely.

Answer 3

This question, and the answer (by User1) which is currently the highest rated, seems very weird to me. I've never before heard this rule to avoid "I am" when on the phone. When people ask for me by name, I might say "This is", but probably say "I am" more frequently (because it is slightly faster).

"I am" sounds a bit more personal; perhaps the older generation preferred more formality when communicating in a less personal fashion, like over the phone? But today, salespeople are certainly encouraged to connect emotionally with people, in order to bond.

Nobody has ever expressed any discomfort with me using "I am".