Posts Tagged ‘SMTP’

Send iCalendar meeting requests for different timezone

Sunday, January 1st, 2012

Usually you define time of an event in relation to UTC time zone.

If you need to define event on 9:00 o’clock in Alaska you simply need
to subtract 9 hours from event time to get the event time in UTC
(18:00:00). 18 – 9 = 9.

It all works great in December (Alaska is UTC-9), but in May, daylight
saving time is in effect in Alaska (Alaska is UTC-8 then).

If the event is recurring, in May, event is going to be held on 10:00
Alaska time (18 – 8 = 10). Which is most likely not what you want.

As the time zones in different parts of world change way to often to reflect these changes in Mail.dll,
you’ll need to specify the time zone when creating new event (including the daylight savings time).

Here’s the sample:

// C#
using Fluent = Lesnikowski.Mail.Fluent;
using Lesnikowski.Client;
using Lesnikowski.Mail;
using Lesnikowski.Mail.Appointments;

Appointment appointment = new Appointment();

// Create time zone
VTimeZone alaska = appointment.AddTimeZone();
alaska.TimeZoneId = "America/Anchorage";

// Define standard time offset
var standardRecurring = new RecurringRule();
standardRecurring.Frequency = Frequency.Yearly;
standardRecurring.ByDay.Add(Weekday.Sunday);
standardRecurring.ByMonths.Add(11);

var standard = new StandardOffset
{
    Name = "AKST",
    Start = new DateTime(1970, 11, 01, 02, 00, 00),
    OffsetFrom = TimeSpan.FromHours(-8),
    OffsetTo = TimeSpan.FromHours(-9),
    RecurringRule = standardRecurring
};

// Define daylight time offset
var daylightRecurring = new RecurringRule();
daylightRecurring.Frequency = Frequency.Yearly;
daylightRecurring.ByDay.Add(new Weekday(2, Weekday.Sunday));
daylightRecurring.ByMonths.Add(3);

var daylight = new DaylightOffset
{
    Name = "AKDT",
    Start = new DateTime(1970, 03, 08, 02, 00, 00),
    OffsetFrom = TimeSpan.FromHours(-9),
    OffsetTo = TimeSpan.FromHours(-8),
    RecurringRule = daylightRecurring
};

alaska.Standard.Add(standard);
alaska.Daylight.Add(daylight);

// Define event
Event e = appointment.AddEvent();
e.Start = new DateTime(2007, 08, 17, 12, 00, 00);
e.End = new DateTime(2007, 08, 17, 12, 30, 00);
e.Summary = "At noon in Alaska";
e.InTimeZone(alaska);

e.SetOrganizer(new Person("Alice", "alice@example.org"));

e.AddParticipant(new Participant(
    "Bob", "bob@example.org", ParticipationRole.Required, true));
e.AddParticipant(new Participant(
    "Tom", "tom@example.org", ParticipationRole.Optional, true));
e.AddParticipant(new Participant(
    "Alice", "alice@example.org", ParticipationRole.Required, true));

Alarm alarm = e.AddAlarm();
alarm.BeforeStart(TimeSpan.FromMinutes(15));

IMail email = Fluent.Mail
    .Text("Status meeting at noon in Alaska.")
    .Subject("Status meeting")
    .From("alice@example.org")
    .To("bob@example.org")
    .To("tom@example.org")
    .AddAppointment(appointment)
    .Create();

using (Smtp smtp = new Smtp())
{
    smtp.Connect("smtp.example.org"); // or ConnectSSL
    smtp.Login("user", "password");
    smtp.SendMessage(email);
    smtp.Close();
}
' VB.NET
Imports Fluent = Lesnikowski.Mail.Fluent
Imports Lesnikowski.Client
Imports Lesnikowski.Mail
Imports Lesnikowski.Mail.Appointments

Dim appointment As New Appointment()

' Create time zone
Dim alaska As VTimeZone = appointment.AddTimeZone()
alaska.TimeZoneId = "America/Anchorage"

' Define standard time offset
Dim standardRecurring = New RecurringRule()
standardRecurring.Frequency = Frequency.Yearly
standardRecurring.ByDay.Add(Weekday.Sunday)
standardRecurring.ByMonths.Add(11)

Dim standard = New StandardOffset() With { _
	.Name = "AKST", _
	.Start = New DateTime(1970, 11, 1, 2, 0, 0), _
	.OffsetFrom = TimeSpan.FromHours(-8), _
	.OffsetTo = TimeSpan.FromHours(-9), _
	.RecurringRule = standardRecurring _
}

' Define daylight time offset
Dim daylightRecurring = New RecurringRule()
daylightRecurring.Frequency = Frequency.Yearly
daylightRecurring.ByDay.Add(New Weekday(2, Weekday.Sunday))
daylightRecurring.ByMonths.Add(3)

Dim daylight = New DaylightOffset() With { _
	.Name = "AKDT", _
	.Start = New DateTime(1970, 3, 8, 2, 0, 0), _
	.OffsetFrom = TimeSpan.FromHours(-9), _
	.OffsetTo = TimeSpan.FromHours(-8), _
	.RecurringRule = daylightRecurring _
}

alaska.Standard.Add(standard)
alaska.Daylight.Add(daylight)

' Define event
Dim e As [Event] = appointment.AddEvent()
e.Start = New DateTime(2007, 8, 17, 12, 0, 0)
e.[End] = New DateTime(2007, 8, 17, 12, 30, 0)
e.Summary = "At noon in Alaska"
e.InTimeZone(alaska)

e.SetOrganizer(New Person("Alice", "alice@example.org"))

e.AddParticipant(New Participant( _
	"Bob", "bob@example.org", ParticipationRole.Required, True))
e.AddParticipant(New Participant( _
	"Tom", "tom@example.org", ParticipationRole.[Optional], True))
e.AddParticipant(New Participant( _
	"Alice", "alice@example.org", ParticipationRole.Required, True))

Dim alarm As Alarm = e.AddAlarm()
alarm.BeforeStart(TimeSpan.FromMinutes(15))

Dim email As IMail = Fluent.Mail _
	.Text("Status meeting at noon in Alaska.") _
	.Subject("Status meeting") _
	.From("alice@example.org") _
	.[To]("bob@example.org") _
	.[To]("tom@example.org") _
	.AddAppointment(appointment) _
	.Create()

Using smtp As New Smtp()
	smtp.Connect("smtp.example.org") 	' or ConnectSSL
	smtp.Login("user", "password")
	smtp.SendMessage(email)
	smtp.Close()
End Using

Reply to an email

Wednesday, December 28th, 2011

You can use Mail.dll to reply to an HTML or plain-text email.

ReplyBuilder class allows you to specify custom HTML and plain-text templates for the reply. Mail.dll will parse HTML extract body part, and build-in template engine will do the rest.

The next great thing is that plain-text version of the email is generated automatically.

// C#

IMail original = ...;

ReplyBuilder replyBuilder = original.Reply();
// You can specify your own custom template:
replyBuilder.HtmlReplyTemplate =
    "[Html]" +
    "<br /><br />" +
    "On [Original.Date] [Original.Sender.Name] wrote:" +
    "<blockquote " +
        "style='margin-left: 1em; " +
        "padding-left: 1em; " +
        "border-left: 1px #ccc solid;'>" +
    "[QuoteHtml]" +
    "</blockquote>";

replyBuilder.Html =
    "Alice, <br/><br/>thanks for your email.";

MailBuilder builder = replyBuilder.ReplyToAll(
    new MailBox("bob@example.org", "Bob"));

// You can add attachments to your reply
//builder.AddAttachment("report.csv");

IMail reply = builder.Create();

using (Smtp smtp = new Smtp())
{
    smtp.Connect("smtp.example.com"); // or ConnectSSL
    smtp.Login("user", "password");
    smtp.SendMessage(reply);
    smtp.Close();
}
' VB.NET

Dim original As IMail = ...

Dim replyBuilder As ReplyBuilder = original.Reply()

' You can specify your own custom template:
replyBuilder.HtmlReplyTemplate = _
    "[Html]" + _
    "<br /><br />" + _
    "On [Original.Date] [Original.Sender.Name] wrote:" + _
    "<blockquote " + _
        "style='margin-left: 1em; " + _
        "padding-left: 1em; " + _
        "border-left: 1px #ccc solid;'>" + _
    "[QuoteHtml]" + _
    "</blockquote>"

replyBuilder.Html = _
    "Alice, <br/><br/>thanks for your email."

Dim builder As MailBuilder = replyBuilder.ReplyToAll( _
    New MailBox("bob@example.org", "Bob"))

' You can add attachments to your reply
'builder.AddAttachment("report.csv")

Dim reply As IMail = builder.Create()

Using smtp As New Smtp()
	smtp.Connect("smtp.example.com")
	smtp.Login("user", "password") ' or ConnectSSL
	smtp.SendMessage(reply)
	smtp.Close()
End Using

Get supported authentication methods (IMAP, POP3, SMTP)

Thursday, October 6th, 2011

You can use SupportedAuthenticationMethodsto retrieve all authentication methods supported by the server:

// C#

using (Imap client = new Imap())
{
    client.ConnectSSL("imap.example.org");
    client.UseBestLogin("user", "password");

    Console.WriteLine("Supported methods:");

    foreach (var method in client.SupportedAuthenticationMethods())
    {
        Console.WriteLine(method.Name);
    }

    Console.WriteLine("Supports CramMD5:");

    bool supportsCramMD5 = client.SupportedAuthenticationMethods()
        .Contains(ImapAuthenticationMethod.CramMD5);

    Console.WriteLine(supportsCramMD5);

    client.Close();
}
' VB.NET

Using client As New Imap()
    client.ConnectSSL("imap.example.org")
    client.UseBestLogin("user", "password")

    Console.WriteLine("Supported methods:")

    For Each method As ImapAuthenticationMethod In client.SupportedAuthenticationMethods()
	    Console.WriteLine(method.Name)
    Next

    Console.WriteLine("Supports CramMD5:")

    Dim supportsCramMD5 As Boolean = client.SupportedAuthenticationMethods() _
        .Contains(ImapAuthenticationMethod.CramMD5)

    Console.WriteLine(supportsCramMD5)

    client.Close()
End Using

For example Gmail produces following output:

Supported method s:
IMAP4rev1
UNSELECT
IDLE
NAMESPACE
QUOTA
ID
XLIST
CHILDREN
X-GM-EXT-1
UIDPLUS
COMPRESS

Supports CramMD5:
False

We take great care for the API to look similar for all protocols (IMAP, POP3, SMTP).

Here’s the sample for POP3:

// C#

using (Pop3 client = new Pop3())
{
    client.ConnectSSL("pop3.example.org");
    client.UseBestLogin("user", "password");

    Console.WriteLine("Supported methods:");

    foreach (var method in client.SupportedAuthenticationMethods())
    {
        Console.WriteLine(method.Name);
    }

    Console.WriteLine("Supports CramMD5:");

    bool supportsCramMD5 = client.SupportedAuthenticationMethods()
        .Contains(Pop3AuthenticationMethod.CramMD5);

    Console.WriteLine(supportsCramMD5);

    client.Close();
}
' VB.NET

Using client As New Pop3()
    client.ConnectSSL("pop3.example.org")
    client.UseBestLogin("user", "password")

    Console.WriteLine("Supported methods:")

    For Each method As Pop3AuthenticationMethod In client.SupportedAuthenticationMethods()
	    Console.WriteLine(method.Name)
    Next

    Console.WriteLine("Supports CramMD5:")

    Dim supportsCramMD5 As Boolean = client.SupportedAuthenticationMethods() _
        .Contains(Pop3AuthenticationMethod.CramMD5)

    Console.WriteLine(supportsCramMD5)

    client.Close()
End Using

Here’s the sample for SMTP:

// C#

using (Smtpclient = new Smtp())
{
    client.Connect("smtp.example.org");
    client.UseBestLogin("smtp", "password");

    Console.WriteLine("Supported methods:");

    foreach (var method in client.SupportedAuthenticationMethods())
    {
        Console.WriteLine(method.Name);
    }

    Console.WriteLine("Supports CramMD5:");

    bool supportsCramMD5 = client.SupportedAuthenticationMethods()
        .Contains(SmtpAuthenticationMethod.CramMD5);

    Console.WriteLine(supportsCramMD5);

    client.Close();
}
' VB.NET

Using client As New Smtp()
    client.Connect("smtp.example.org")
    client.UseBestLogin("user", "password")

    Console.WriteLine("Supported methods:")

    For Each method As SmtpAuthenticationMethod In client.SupportedAuthenticationMethods()
	    Console.WriteLine(method.Name)
    Next

    Console.WriteLine("Supports CramMD5:")

    Dim supportsCramMD5 As Boolean = client.SupportedAuthenticationMethods() _
        .Contains(SmtpAuthenticationMethod.CramMD5)

    Console.WriteLine(supportsCramMD5)

    client.Close()
End Using

Get supported server extensions (IMAP, POP3, SMTP)

Thursday, October 6th, 2011

You can use SupportedExtensionsmethod to retrieve all protocol extensions supported by the server:

// C#

using (Imap client = new Imap())
{
    client.ConnectSSL("imap.example.org");
    client.UseBestLogin("user", "password");

    Console.WriteLine("Supported extensions:");

    foreach (ImapExtension extension in client.SupportedExtensions())
    {
        Console.WriteLine(extension.Name);
    }

    Console.WriteLine("Supports IDLE:");

    bool supportsIdle = client.SupportedExtensions()
        .Contains(ImapExtension.Idle);

    Console.WriteLine(supportsIdle);

    client.Close();
}
' VB.NET

Using client As New Imap()
    client.ConnectSSL("imap.example.org")
    client.UseBestLogin("user", "password")

    Console.WriteLine("Supported extensions:")

    For Each extension As ImapExtension In client.SupportedExtensions()
	    Console.WriteLine(extension.Name)
    Next

    Console.WriteLine("Supports IDLE:")

    Dim supportsIdle As Boolean = client.SupportedExtensions() _
        .Contains(ImapExtension.Idle)

    Console.WriteLine(supportsIdle)

    client.Close()
End Using

For example Gmail produces following output:

Supported extensions:
IMAP4rev1
UNSELECT
IDLE
NAMESPACE
QUOTA
ID
XLIST
CHILDREN
X-GM-EXT-1
UIDPLUS
COMPRESS

Supports IDLE:
True

We take great care for the API to look similar for all protocols (IMAP, POP3, SMTP).

Here’s the sample for POP3:

// C#

using (Pop3 client = new Pop3())
{
    client.ConnectSSL("pop3.example.org");
    client.UseBestLogin("user", "password");

    Console.WriteLine("Supported extensions:");

    foreach (Pop3Extension extension in client.SupportedExtensions())
    {
        Console.WriteLine(extension.Name);
    }

    Console.WriteLine("Supports TOP:");

    bool supportsTop= client.SupportedExtensions()
        .Contains(Pop3Extension.Top);

    Console.WriteLine(supportsTop);

    client.Close();
}
' VB.NET

Using client As New Pop3()
    client.ConnectSSL("pop3.example.org")
    client.UseBestLogin("user", "password")

    Console.WriteLine("Supported extensions:")

    For Each extension As Pop3Extension In client.SupportedExtensions()
	    Console.WriteLine(extension.Name)
    Next

    Console.WriteLine("Supports TOP:")

    Dim supportsTop As Boolean = client.SupportedExtensions() _
        .Contains(Pop3Extension.Top)

    Console.WriteLine(supportsTop)

    client.Close()
End Using

Here’s the sample for SMTP:

// C#

using (Smtpclient = new Smtp())
{
    client.Connect("smtp.example.org");
    client.UseBestLogin("smtp", "password");

    Console.WriteLine("Supported extensions:");

    foreach (SmtpExtension  extension in client.SupportedExtensions())
    {
        Console.WriteLine(extension.Name);
    }

    Console.WriteLine("Supports STARTTLS:");

    bool supportsStartTLS = client.SupportedExtensions()
        .Contains(SmtpExtension.StartTLS);

    Console.WriteLine(supportsStartTLS);

    client.Close();
}
' VB.NET

Using client As New Smtp()
    client.Connect("smtp.example.org")
    client.UseBestLogin("user", "password")

    Console.WriteLine("Supported extensions:")

    For Each extension As SmtpExtension In client.SupportedExtensions()
	    Console.WriteLine(extension.Name)
    Next

    Console.WriteLine("Supports STARTTLS:")

    Dim supportsStartTLS As Boolean = client.SupportedExtensions() _
        .Contains(SmtpExtension.StartTLS)

    Console.WriteLine(supportsStartTLS)

    client.Close()
End Using

Send encrypted email using S/MIME

Wednesday, January 26th, 2011

Sending encrypted and signed S/MIME messages has never been easier:

// C# version

IMail email = Mail
    .Html("<html><body>Encrypted and signed</body></html>")
    .Subject("Encrypted and signed")
    .From(new MailBox("email@in-the-certificate.com", "Alice"))
    .To(new MailBox("bob@mail.com", "Bob"))
    .AddAttachment(@"c:report_2010.pdf")
    .SignWith(new X509Certificate2("SignCertificate.pfx", ""))
    .EncryptWith(new X509Certificate2("EncryptCertificate.pfx", ""))
    .EncryptWith(new X509Certificate2("BobsCertificate.pfx", ""))
    .Create();

using (Smtp client = new Smtp())
{
    client.ConnectSSL("smtp.example.com");
    client.Login("user", "password");
    client.SendMessage(email);
    client.Close();
}
' VB.NET version

Dim email As IMail = Mail _
	.Html("<html><body>Encrypted and signed</body></html>") _
	.Subject("Encrypted and signed") _
	.From(New MailBox("email@in-the-certificate.com", "Alice")) _
	.To(New MailBox("bob@mail.com", "Bob")) _
	.AddAttachment("c:report_2010.pdf") _
	.SignWith(New X509Certificate2("SignCertificate.pfx", "")) _
	.EncryptWith(New X509Certificate2("EncryptCertificate.pfx", "")) _
	.EncryptWith(New X509Certificate2("BobsCertificate.pfx", "")) _
	.Create()

Using client As New Smtp()
	client.ConnectSSL("smtp.example.com")
	client.Login("user", "password")
	client.SendMessage(email)
	client.Close()
End Using

Remember to encrypt your emails with both sender’s and receiver’s certificates.
This way both parties are able to decrypt such emails.

Common errors you may encounter:

  • Please use the PersistKeySet flag when loading from file (new X509Certificate2(_certificatePath, “”, X509KeyStorageFlags.PersistKeySet);) and adding to store
  • “Bad key” exception message means that certificate was not for key exchange – makecert needs an extra parameter to create certificate that can be used for symmetric algorithm key exchange: -sky exchange.
  • “the enveloped data-message does not contain the specified recipient” means that certificate with the private key is not deployed into the current account/local machine personal store, or not in the certificates list

You can use following commands in VisualStudio Command Prompt to create test certificate:

makecert.exe -pe -r -sv Test_Keys.pvk -n "CN=John Doe,E=email@in-the-certificate.com" -sky exchange Test.cer

pvk2pfx.exe -pvk Test_Keys.pvk -spc Test.cer -pfx Test.pfx