B4A Library New Net library - Android FTP, SMTP and POP3

The Net library supports FTP, SMTP and POP3 protocols. This library replaces the FTP library. Both regular connections and SSL connections are supported.
SMTP - Allows to directly connect to SMTP mail servers and send mails, including Html messages and attachments.
POP3 - Allows to directly connect to POP3 mail servers and download messages. Currently the messages are not parsed. The raw string is returned. You can use MailParser class to parse the raw messages.

Installation instructions:
- Download the attach file.
- Copy Net.xml and Net.jar to the additional libraries folder. Make sure that there are no older copies in the internal libraries folder.

V1.81 - latest version
V1.80 - SMTP, POP and FTP can be configured to use a custom trust manager. This allows accepting invalid certificates.

V1.77 - New Sender.MailFrom field. Allows setting the mail address that is sent with the MAIL command. By default it is the same as the Username field.

V1.75 - Adds a configurable timeout parameter - FTP.TimeoutMs. Default timeout is set to 60000 (60 seconds).

V1.70 - Adds support for calling with Wait For: https://www.b4x.com/android/forum/threads/b4x-net-library-ftp-smtp-pop-with-wait-for.84821/
SMTP.AdditionalHeaders map. Allows adding headers to the messages.

V1.63 - Fixes an issue with SMTP mails with attachments. The closing boundary was previously missing.
V1.62 - Fixes an issue with SMTP in StartTLS mode.
V1.61 - Fixes an issue in SMTP related to the content encoding not being set in multipart messages.

V1.60 - New method: FTP.AppendFile. Similar to UploadFile. Appends the data to an existing file if such exists. It sends the APPE FTP command.

V1.53 - Fixes an issue with FTP.CloseNow and SSL connections.

V1.52 - Adds support for different types of authentication methods (SMTP): http://www.b4x.com/android/forum/th...d-ftp-smtp-and-pop3.10892/page-11#post-232432

V1.51 is released. Fixes an issue with FTP over SSL explicit mode.

V1.50 is released. See this link: http://www.b4x.com/android/forum/th...d-ftp-smtp-and-pop3.10892/page-10#post-231145

V1.37 is released. This version removes the automatic escaping of '=' characters in SMTP messages. To implement it in your code you should write:

SMTP.Body = SMTP.Body.Replace("=", "=3D")

V1.35 is released. This version adds support for STARTTLS mode.
Unlike UseSSL mode the connection is "upgraded" to a secured connection only after the client sends the STARTTLS command.
Most of the popular smtp servers support this mode, usually on port 587.

Sub Activity_Create(FirstTime As Boolean)
   If FirstTime Then
      smtpClient.Initialize("smtp.gmail.com", 587, "xxx@gmail.com", "yyy", "SmtpClient")
      smtpClient.StartTLSMode = True
   End If
End Sub

 

[Stuart McLachlan]

Bug in SMTP? BCC recipients can see all other BCCs

That's not a bug, it's a feature

It's actually a perfectly valid implementation of the standard.

RFC 5322, Para 3.6.3. Note the sentence in parentheses at the end of the quote which describes your desired implementation as just one way of handling it.

"There are three ways in which the "Bcc:" field is used. In the first case, when a message containing a "Bcc:" field is prepared to be sent, the "Bcc:" line is removed even though all of the recipients (including those specified in the "Bcc:" field) are sent a copy of the message. In the second case, recipients specified in the "To:" and "Cc:" lines each are sent a copy of the message with the "Bcc:" line removed as above, but the recipients on the "Bcc:" line get a separate copy of the message containing a "Bcc:" line. (When there are multiple recipient addresses in the "Bcc:" field, some implementations actually send a separate copy of the message to each recipient with a "Bcc:" containing only the address of that particular recipient.)"

FWIW, this is from a Help screen in my preferred email program - Pegasus Mail:
"Suppress BCC field listings in outgoing mail BCC (Blind Carbon Copy) is a useful, but poorly-standardized feature. There are at least three ways a BCC field could be written into a message: it could be omitted altogether; it could contain only each individual recipient's address; or it could contain theaddresses of all people receiving the BCC. By default, Pegasus Mail lists all the BCC recipients in the BCC field of mail it sends: if you would prefer that no addresses were shown in the field, then check this control. When this option is turned on, theBCC field will simply contain the text "(Suppressed)", without any addresses."

That could usefully be an option in any future version of the library.

 

[boten]

Still strange. When sending email to multiple BCCs using gmail (in browser, gmail.com) each BCC recipient sees only the "To: address" AND its own address (in bcc filed).
BUT, when sending from app using SMTP, each BCC recipient also sees (in addition to the above) all other BCC recipients, which defies the intention of BCC.

 

[wl]

I guess then this depends on how the gmail email client works in respect to the SMTP class. AFAIK the SMTP server as such will only send individual messages.

 

[Stuart McLachlan]

>which defies the intention of BCC

Your idea of the intent of BCC is just that, your idea. GMail doing it that way doesn't mean that it is the only or "correct" implementation.

If you read the quote above from the RFC, the library's way of doing it is the second method described, your desired miplementation is the third (in parenthesized) method. Which implies, if anything, that the library implementation is more common that your desired implementation. As I also pointed out, the library's method is also the default for Pegasus Mail - a decision which was reached after a great deal of thought went into the design.

 

[Stuart McLachlan]

I guess then this depends on how the gmail email client works in respect to the SMTP class. AFAIK the SMTP server as such will only send individual messages.

A properly designed SMTP Server will only send one copy of an email to each addressee domain, regardless of how many addresses at that domain are in the To, CC and BCC headers. Note that the SMTP component of the library is not a full SMTP server. It just provides basic Message Submission Agent and Message Transmission Agent (MSA/MTA) capabilities to your app.

 

[wl]

This is exactly what I meant ...

 

[boten]

I'm not talking about who gets a copy of the message - all addresses should receive the message itself, whether these addresses are in TO: CC: or BCC: fields.

My point is that: If you send a message to addr1, put in CC: addr2, put in BCC: addr3 and addr4 then
addr1 can see that message was also sent to addr2
addr2 can see that message was also sent to addr1
addr3 can see that message was also sent to addr1 and addr2
and so should addr4.
BUT: neither addr1, nor addr2 sees that addr3 & addr4 also received it
addr3 won't see addr4, and addr4 won't see addr3
That's how BCC originally intended to work, replicating the method when messages where typed & copied with carbon paper.

As for the implementation in the library:
The Gmail app in my phone (and I assume in any android device) treats BCC as was originally meant by BCC - BLIND carbon copy. That's the reason for BCC. I you want all recipients to see the e-mail address of all other recipients you can either send to all recipients (TO: ) or put all of then in the CC: field.

The SMTP object in the Net library has both CC and BCC fields. If BCC is there "only for decoration" - it should be so stated, But if the intention is to provide functionality similar to most e-mail programs (let Pegasus fly on its own) then addresses added to the BCC list should be hidden from all other recipients.

 

[mjtaryan]

My interest at the moment is transferring large remotely stored and organized documents using FTP. Is there a full tutorial for the Net library? Thanks.

 

[Erel]

http://www.b4x.com/search?query=FTP+Tutorial

 

[LaryLee]

I got a problem , "downloadService", red-words within StartService(DownloadService).
I know that is I need to add some modules, or lack import some libiraies.
Please help me, Thanks

 

[MotoMusher]

View attachment 20519
I got a problem , "downloadService", red-words within StartService(DownloadService).
I know that is I need to add some modules, or lack import some libiraies.
Please help me, Thanks

Do you have a service that you created called "DownloadService"? If so you should do StartService("DownloadService"). The name of the service is passed as a string. If you don't have a download service, then to create one, Go to the Project menu, then "Add New Module", then choose "Service Module" and put your code in there.

 

[Erel]

@LaryLee you should start a new thread for this question. It is not related to the Net library. I guess that you are referring to an old example. You should use HttpUtils2 to download instead.

 

[LaryLee]

@LaryLee you should start a new thread for this question. It is not related to the Net library. I guess that you are referring to an old example. You should use HttpUtils2 to download instead.

Thanks, Yes Maybe I refer to an old example.

 

[LaryLee]

I try to download a text file from a web site

My B4A partial prog is following :

But during debug , the result I got is :

Prog can't log into web server or folder path is wrong ?
Please help me, thanks

 

[Erel]

Your code is incorrect. See the tutorial: Android FTP tutorial

Note that it is better to post the code instead of a screenshot.

 

[LaryLee]

Your code is incorrect. See the tutorial: Android FTP tutorial

Note that it is better to post the code instead of a screenshot.

Thanks, I will keep in my mind to post code.

 

[Kwame Twum]

hi everyone, I tried uploading a file from my sdcard to a server and I get the following in the logs

/palztechgroup.com/wwwroot/00001.vcf, Success=false
javax.net.ssl.SSLProtocolException: SSL handshake aborted: ssl=0x344770: Failure in SSL library, usually a protocol error
error:140770FC:SSL routines:SSL23_GET_SERVER_HELLO:unknown protocol (external/openssl/ssl/s23_clnt.c:683 0xad1275cc:0x00000000)

The credentials passed to FTP.Initialise work on a FTP client
This is the sub that handles the upload:

Sub attch_Click
    Dim dial As FileDialog
    dial.FilePath= File.Combine(File.DirRootExternal, "/")
    If dial.Show("Select a file", "Lego!", "Cancel","",Null)=-1 Then
        FTP.UseSSL = True
        FTP.PassiveMode = True
        ProgressDialogShow("Attempting to upload...")
        FTP.UploadFile(File.DirRootExternal, dial.ChosenName, True, "/palztechgroup.com/wwwroot/" & dial.ChosenName)
        FTP.Close
        ProgressDialogHide
    End If
End Sub

What can the problem be? Need help

 

[Erel]

Have you tested the FTP client on the same device?

 

[Kwame Twum]

Have you tested the FTP client on the same device?

I haven't... What I meant was that the username and password used in the Initialising stage are correct ( I've tried it in FileZilla)..

 

[Erel]

The problem is not with the username and password. The problem is with the certificate or specific SSL protocol which seems to be not supported.