How to user erlang gen_smtp to send html-formatted email? - html

Question

gen_smtp can be found here
What I want is to let the content of email supports HTML tag, such as <strong>Hello</strong>
Will display as Hello.

Answer 1

Look at https://github.com/selectel/pat. It's an easy to use SMTP client and you can use any text, including html tags as body of the message.

Answer 2

See the gen_smtp mimemail tests for an example of multipart/alternative messages:
Email = {<<"text">>, <<"html">>, [
{<<"From">>, <<"me#example.com">>},
{<<"To">>, <<"you#example.com">>},
{<<"Subject">>, <<"This is a test">>}],
#{content_type_params => [
{<<"charset">>, <<"US-ASCII">>}],
disposition => <<"inline">>
},
<<"This is a <strong>HTML</strong> message with some non-ascii characters øÿ\r\nso there">>},
Encoded = mimemail:encode(Email)

Answer 3

The answer given by #Ward Bekker is fundamentally correct but it took me a while to make it work as the mimemail:encode/1 expects a proplist not a map which the example shows.
I used Erlang Erlang/OTP 23 [erts-11.0.3] and it failed with:
** exception error: no function clause matching proplists:get_value(<<"content-type-params">>, #{disposition => <<"inline">>,<<"content-type-params">> => [{<<"charset">>,<<"US-ASCII">>}]},[]) (proplists.erl, line 215)
in function mimemail:ensure_content_headers/7 (/Users/sean/Documents/code/erlang/scofblog/_build/default/lib/gen_smtp/src/mimemail.erl, line 661)
The following is the modified code and the encoded output:
Email = {
<<"text">>,
<<"html">>,
[
{<<"From">>, <<"me#example.com">>},
{<<"To">>, <<"you#example.com">>},
{<<"Subject">>, <<"This is a test">>}
],
[{<<"content-type-params">>, [{<<"charset">>, <<"US-ASCII">>}]},
{<<"disposition">>, <<"inline">>}
],
<<"This is a <strong>HTML</strong> øÿ\r\nso there">>
}.
62> mimemail:encode(Email).
<<"From: me#example.com\r\nTo: you#example.com\r\nSubject: This is a test\r\nContent-Type: text/html;\r\n\tcharset=US-ASCII\r\nCon"...>>
Hope that saves some head scratching.