MailMessage.To.Add() 抛出异常：“在邮件标题中发现无效字符：','。”

Question

I am getting this error when I am using it in sharepoint project, while in console app its working fine

I am using MailMessage class to send email using SMTP . But when I trying to add user to 'To' property I am getting {"An invalid character was found in the mail header: ','."} exception, which I think something fishy is happening here as ',' is allowed to separate multiple users . Adding multiple user

** Multiple e-mail addresses must be separated with a comma character (",").**

MailMessage mailMessage = new MailMessage();

 mailMessage.To.Add("amir_khan@enter.com,walter_white@yahoo.com,");

Answer 1

Got the culprit: It's the extra comma( , ) at the end of last email address

mailMessage.To.Add("amir_khan@enter.com,walter_white@yahoo.com,");

Just removed that and voila! its working. Don't know why it's working in console application but not in sharepoint :(

mailMessage.To.Add("amir_khan@enter.com,walter_white@yahoo.com");

If this does not work in SharePoint then please add each address separately onto MailMessage object like below;

foreach (var address in StringofEmails.Split(",")) {
MailMessage.To.Add(new MailAddress(address.Trim(), ""));

}

Answer 2

I got the error even though I don't have a comma at the end. It turns out that I need to leave a space after the comma

I have to change my code from a string.Join(",", emailList) to string.Join(", ", emailList)

Following didn't work for me.

mailMessage.To.Add("amir_khan@enter.com,walter_white@yahoo.com");

Following worked for me(Observe that there is space after the comma).

mailMessage.To.Add("amir_khan@enter.com, walter_white@yahoo.com");

Answer 3

I can't replicate this. The above code works for me. Maybe try to add them using a seperate 'To' each time.

mailMessage.To.Add(x);
mailMessage.To.Add(y);

Answer 4

I had to update a project with nicer looking emails and I published the web project and got this error.

Mine was from some debug code in which

currentUser = myname@mycompany.com   

got added

MailAddress mailAddressUser = new MailAddress(currentUser + "@mycompany.com");

Essentially:

myname@mycompany.com@mycompany.com    

So instead of an issue with a trailing comma, literally another @

Answer 5

In my case I forgot to filter out users without email, so I was forming my list of emails like this:

username1@ldomain.com
username2@domain.com
@domain.com  //PROBLEM HERE
username3@linamar.com