[Feature Req] Interface that accept To/CC with a single string

[suntong]

Is your feature request related to a problem? Please describe.

Please consider adding/allowing passing a single string to To/CC. Currently there is an extra check preventing it:

failed to set To address: failed to parse mail address "a1@gmail.com,a2@gmail.com", mail: expected single address, got ",a2@gmail.com"

When using

if err := m.To("a1@gmail.com,a2@gmail.com"); err != nil {

in https://go-mail.dev/getting-started/introduction/#hl-5-13

Reason being:

• It is perfectly fine to set the "To:" header to something like "Alice <alice@example.com>, Bob <bob@example.com>, Eve <eve@example.com>" in plain email, so such extra checking is too restrictive.
• I understand that there might be extra checking on the email address format checking, but since the basic text based unix email doesn't check it, such extra checking can be optional, IMHO. After all, if the user made mistakes in their to/cc email address, they will know eventually.
• And the most important thing is, to add more recipients, I have to change my Go code to do that, whereas the common sense/practice is to change data, not to change code, when covering different cases.

Describe the solution you'd like

Adding/allowing passing a single string to To/CC.

I can work on PR for that.

Describe alternatives you've considered

No response

Additional context

No response

[wneessen]

Hi @suntong,

thanks for the feature request. I see your need here and I think it might be a good addition to go-mail. To not break any current code, I suggest something like m.ToFromString() and m.CcFromString(). If you'd like a provide a PR, that'll be appreciated. Otherwise I'll put this request on the todo list for the next release.

[suntong]

Thanks for the confirmation. I'll make a try...

[james-d-elliott]

This could be handled locally fairly easily too:

if err := m.To(strings.Split("a1@gmail.com,a2@gmail.com", ",")...); err != nil {

[suntong]

indeed!

[wneessen]

Thanks for the PR @suntong, but I feel that adding complexity SetAddrHeader should not be the desired solution. As either To(), Cc() and Bcc() already accept slices of strings, @james-d-elliott's solution should probably be preferred by just adding helper methods like:

func (m *Msg) ToFromSimpleString(v string) error {
    return m.To(strings.Split(v)...);
}

or something similar. This let's us stay true with the KISS principle.

[suntong]

Yeah, agree.

[suntong]

should probably be preferred by just adding helper methods like ...
Otherwise I'll put this request on the todo list for the next release.

That'd be great, if possible.

Reopen it again, and feel free to close it anytime.