An invalid character was found in the mail header: ','

i am using sent smtp message .my excel has no comma still its giving this error.if i have 2 emails comma separated still its giving error.

they should be separated by a semicolon (;), not a comma (,).

Use semicolons (;) instead of commas (,).

but i also tried with single email id in excel still its giving the same error

It might contains extra spaces or hidden characters clean it before passing into SMTP

Hi @SSD
Can you show a demo input and how you are accessing it?

@SSD

As per your error,
Use semicolon in the place of comma

and even you are using single email id also getting error means may be your email id is wrong check properly and use

Hello, looks related to recipients email. Be careful of not adding the separator caracter in the end.

For instance this is correct

JohnDoe@gmail.com;JanneDoe@gmail.com"

This is not

JohnDoe@gmail.com;JanneDoe@gmail.com;"