(Chilkat2-Python) Send HTML Email with External CSS as Related Item

Demonstrates how to compose an HTML email with an external CSS file included as a related item and referenced by CID (Content-ID).

Chilkat2 Python Downloads

install with pip
pip3 install chilkat2
or download... Python Module for Windows, Linux, Alpine Linux, MacOS, Solaris

import sys
import chilkat2

# This example requires the Chilkat API to have been previously unlocked.
# See Global Unlock Sample for sample code.

# The mailman object is used for sending and receiving email.
mailman = chilkat2.MailMan()

# Use your SMTP server hostname.  This example uses office365, but it could be any SMTP server..
mailman.SmtpHost = "outlook.office365.com"
mailman.SmtpPort = 587
mailman.StartTLS = True

# Set the SMTP login/password
mailman.SmtpUsername = "OFFICE365-SMTP-LOGIN"
mailman.SmtpPassword = "OFFICE365-SMTP-PASSWORD"

# Create a new email object
email = chilkat2.Email()
email.Subject = "HTML Email with embedded CSS"
email.From = "Chilkat Support <my-office365-user@mydomain.com>"
email.AddTo("Chilkat Support","support@chilkatsoft.com")

sbCss = chilkat2.StringBuilder()
bCrlf = True
sbCss.AppendLine("body {",bCrlf)
sbCss.AppendLine("    background-color: powderblue;",bCrlf)
sbCss.AppendLine("}",bCrlf)
sbCss.AppendLine("h1 {",bCrlf)
sbCss.AppendLine("    color: blue;",bCrlf)
sbCss.AppendLine("}",bCrlf)
sbCss.AppendLine("p {",bCrlf)
sbCss.AppendLine("    color: red;",bCrlf)
sbCss.AppendLine("}",bCrlf)

# It's possible to add a CSS file directly by calling AddRelatedFile.
# This example will add the CSS from a string.
filenameInHtml = "styles.css"
contentIdCss = email.AddRelatedString(filenameInHtml,sbCss.GetAsString(),"utf-8")
if (email.LastMethodSuccess != True):
    print(email.LastErrorText)
    sys.exit()

# The src attribute for the image tag is set to the contentIdCss:
sbHtml = chilkat2.StringBuilder()
sbHtml.AppendLine("<!DOCTYPE html>",bCrlf)
sbHtml.AppendLine("<html>",bCrlf)
sbHtml.AppendLine("<head>",bCrlf)
sbHtml.AppendLine("  <link rel=\"stylesheet\" href=\"cid:CONTENT_ID_CSS\">",bCrlf)
sbHtml.AppendLine("</head>",bCrlf)
sbHtml.AppendLine("<body>",bCrlf)
sbHtml.AppendLine("",bCrlf)
sbHtml.AppendLine("<h1>This is a heading</h1>",bCrlf)
sbHtml.AppendLine("<p>This is a paragraph.</p>",bCrlf)
sbHtml.AppendLine("",bCrlf)
sbHtml.AppendLine("</body>",bCrlf)
sbHtml.AppendLine("</html>",bCrlf)

numReplacements = sbHtml.Replace("CONTENT_ID_CSS",contentIdCss)

email.SetHtmlBody(sbHtml.GetAsString())

success = mailman.SendEmail(email)
if (success != True):
    print(mailman.LastErrorText)
else:
    print("Mail Sent!")