Solved

How to insert line feeds in stringbuilder for SMTP email body

Posted on 2006-06-14
2
3,278 Views
Last Modified: 2012-06-27
Hi folks,

My first post on EE and hopefully one that will help others (once solved) who have stumbled across this issue.  I'm new to the point system, so hopefully I have valued this appropriately. If your web app generates email and your email is often misformated with exclamations points, read on.

I have a web application that generates an HTML email back to the user. The email is created dynamically and is different for each user. The body of the email is generated by creating an VB.Net Stringbuilder object (sb) and basically sb.Appending various HTML elements together. My guess is this is a fairly common usage.

For example, if I know the first name of the user, things start out like this:

        If firstName.Trim <> "" Then
            sb.Append("<p style=""margin-top: 0; margin-bottom: 0""><font face=""Arial"" style=""font-size: 11pt"">Dear " & firstName.Trim & ",</font><br>&nbsp;</p>")
        End If

Various paragraphs and info are continuously sb.appended and then the entire SB is converted to a string and passed to an email function. This string can be quite long. 5000 - 10000 characters.

The email function is pretty straightforward. The string is assigned to the email.Body and off it goes (try catch block not shown). The key to this problem is that it goes to an SMTP email server. I've not hit this issue on other email servers.

        emailMessage.BodyFormat = Mail.MailFormat.Html
        emailMessage.Body = big string assigned here
        System.Web.Mail.SmtpMail.SmtpServer = System.Configuration.ConfigurationSettings.AppSettings("MailSvr")
        System.Web.Mail.SmtpMail.Send(emailMessage)

What I noticed immediately is that our host email server seemed to be inserting carriage returns into the body of the message. Most times this just appears as an exclamation point ! and space in the middle of text, but sometimes it really whacks the HTML (especially when it hits in the middle of a tag). After repeated denials from the host that the email server had anything to do with it (wrong!) and lots of searching, I finally discovered that the SMTP server does add carriage returns to email when a line is greater than 990 characters. Apparently the smtp_line_length_limit defaults to 990 and smtp then inserts "<CR><LF><SPACE>" into the long lines.

So that sounded reasonably easy to fix and I happily added "&#10" throughout my sb.Append lines. Only problem, that doesn't seem to solve the problem. Still got the breaks at 990 characters.  I also tried "<LF>" and that seemed to make things better - the exclamation points were gone (the CR part, I think), but still got the spaces every 990 chars.

So the question after all this is, "In VB.net, how do you add a line feed to a stringbuilder object that is recognized by SMTP?"  BTW, <br> doesn't seem to count as a line feed and I'm pretty sure vbcrlf is not the answer.

Thanks in advance and for reading this far.
Dave Hunt
davehunt00








0
Comment
Question by:davehunt00
2 Comments
 
LVL 7

Accepted Solution

by:
pradeepsudharsan earned 125 total points
ID: 16908728
Hai,
plz  use vbCrLf

--Pradeep
0
 
LVL 9

Expert Comment

by:bele04
ID: 16909104
SMTP has a limit of 76 characters per line...try adding a vbCrLf after the 76th character or if that doesn't work try adding two vbCrLf to the end of the string that you will be adding to the stringbuilder
0

Featured Post

Is Your Active Directory as Secure as You Think?

More than 75% of all records are compromised because of the loss or theft of a privileged credential. Experts have been exploring Active Directory infrastructure to identify key threats and establish best practices for keeping data safe. Attend this month’s webinar to learn more.

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

Suggested Solutions

Lots of people ask this question on how to extend the “MembershipProvider” to make use of custom authentication like using existing database or make use of some other way of authentication. Many blogs show you how to extend the membership provider c…
In .NET 2.0, Microsoft introduced the Web Site.  This was the default way to create a web Project in Visual Studio 2005.  In Visual Studio 2008, the Web Application has been restored as the default web Project in Visual Studio/.NET 3.x The Web Si…
Migrating to Microsoft Office 365 is becoming increasingly popular for organizations both large and small. If you have made the leap to Microsoft’s cloud platform, you know that you will need to create a corporate email signature for your Office 365…
With the power of JIRA, there's an unlimited number of ways you can customize it, use it and benefit from it. With that in mind, there's bound to be things that I wasn't able to cover in this course. With this summary we'll look at some places to go…

863 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question

Need Help in Real-Time?

Connect with top rated Experts

20 Experts available now in Live!

Get 1:1 Help Now