Voicemail
Voicemail is included with your service. Voicemail will take messages for you when you are unable to take calls.
The following are key presses that control what your voicemail will do:
• 1 Rewinds 6 seconds. Press 11 to rewind to the beginning
• 2 Pause
• 3 Fast forward 6 seconds. Press 33 fast forward to the end
• 4 Slow down
• 66 Speed up. Press 6 for normal speed
• 7 Delete message
• 9 Save message
• * Interrupt outgoing message to enter passcode when accessing voicemail from an external phone or if you have your phone set to require password when accessing it from the handset
• # skip message
Change the length of time before your voicemail picks up:
Your voicemail can be configured so that it will pick up from 5 seconds to 30 seconds. To change the length of time for the voicemail service to pick up the line enter the following:
• **61*+18056377243**30# This will configure your voicemail to answer after 30 seconds of ringing. If you wish your voicemail to answer in a shorter time change the final value from 30 to another number as little as 5.

Picture Messaging
By default, Picture Messaging isn't enabled for the MDA. To enable Picture Messaging: Send a picture to your own phone number in the MMS section of Outlook.
This signals to the T-Mobile network that your phone is picture messaging capable, and pictures will be received in your MMS section of your phone. Until you do this, you'll receive text messages instead with unclickable links to a website that doesn't work - so make this one of the first things you do after starting T-Mobile service!

GSM Service Codes
Some characters explained
• activate
• * register and activate
• # check status
• # unregister
• ## unregister and deactivate
The codes are used by for example writing ##002# and the pressing the key corresponding to "Send". There are some codes where you are not supposed to press "Send". These codes are only to be used within the phone itself and they don't take any use of the net services. The symbol © signifies pressing the send/talk key on your cellphone.
Not all codes are functioning in all nets. It depends on what the operators have included in their software.
If a phone number is expected you should enter it in the international format e.g. +13115552368. This will always do the trick whatever net you are logged in to.
The codes are divided into different categories:
Security, Call forwarding/diversion, Barring, Call Waiting, CLIP: Incoming Call Presentation Number (Caller ID), COLP: Current Reached Number Presentation (If called number was diverted to another number), GSM network service codes

Security
Command string Description Change call barring code **03*OldCode*NewCode*NewCode#©
Change call barring code **03*OldCode*NewCode*NewCode#©
Change PIN code **04*OldPIN*NewPIN*NewPIN#©
Change PIN2 code **042*OldPIN2*NewPIN2*NewPIN2#©
Unlock PIN code (PUK) (when PIN is entered wrong 3 times) **05*PUK*NewPIN*NewPIN#©
Unlock PIN2 code (PUK2)**052*PUK2*NewPIN2*NewPIN2#©
Activate PIN code (works on some Sony models) *09*PIN#©
Deactivate PIN code (works on some Sony models) #09*PIN#©
Display IMEI *#06#©
Default T-Mobile SIM PIN's: PIN1= 1234 PIN2= 5678

Forwarding/Diverting
I tried the 'activate' codes below on my T-Mobile phone and they did not work. However, when I used a slight variation, they did work. I'll give just one example: Unconditional Call Forwarding - To activate, I used **21*number# - and not **21number#. The '*' after 21 was required for me. I suspect all those ** codes may require this.
Command string Description
De-register all call diversions ##002#©
Set all configured call diversions to number and activate **004*number#©
De-register all configured call diversions (no answer , not reachable, busy)##004#©
Unconditionally divert all calls **21number#©
Activate Unconditionally divert all calls to number and activate **21number#©
Activate unconditionally divert all calls *21#©
De-register unconditionally divert all calls ##21#©
Deactivate unconditionally divert all calls #21#©
Check status of unconditionally divert all call *#21#©
Divert on no answer to number and activate **61*number#©
Activate divert on no answer *61#©
Divert on not reachable to number and activate **62*number#©
Activate divert on not reachable *62#©
De-register divert on not reachable ##62#©
Deactivate divert on not reachable #62#©
Check status of divert on not reachable *#62#©
Divert on busy to number and activate /td> **67*number#©
Activate divert on busy *67#©
De-register divert on busy ##67#©
Deactivate divert on busy #67#©
Check status of divert on busy *#67#©
Change number of seconds of ringing for the given service before diverting a call (such as on no answer). Seconds must be a value from 5 to 30. De-registering the same divert will also delete this change!**service*number**seconds#© (Service numbers, see below)

Barring Call
Activate barr all outgoing calls (see Security to set code)**33*code#©
Deactivate barr all outgoing calls #33*code#©
Check status of barr all outgoing calls *#33#©
Activate barr all calls **330*code#©
Deactivate barr all calls #330*code#©
Check status of barr all calls /td> *#330*code#©<
Activate barr all outgoing international calls **331*code#©
Deactivate barr all outgoing international calls #331*code#©
Check status of barr all outgoing international calls *#331#©
Activate barr all outgoing international calls except to home country **332*code#©
Deactivate barr all outgoing international calls except to home country #332*code#©
Check status of barr all outgoing international calls except to home country *#332#©
Activate barr all outgoing calls **333*code#©
Deactivate barr all outgoing calls #333*code#©
Check status of barr all outgoing calls *#333#©
Activate barr all incoming calls **35*code#©
Deactivate barr all incoming calls #35*code#©
Check status of barr all incoming calls *#35#©
Activate barr all incoming calls when roaming **351*code#©
Deactivate barr all incoming calls when roaming #351*code#©
Check status of barr all incoming calls when roaming *#351#©
Activate barr all incoming calls **353*code#©
Deactivate barr all incoming calls #353*code#©
Check status of barr all incoming calls *#353#©

Call Waiting
Activate call waiting *43*#©
Deactivate call waiting #43##©
Check status of call waiting *#43#©
Calling Line Identification The following only works if CLIP and CLIR are enabled.(ask your service provider)

CLIP: Incoming Call Presentation Number
Activate CLIP **30#©
Deactivate CLIP ##30#©
Check status of CLIP *#30#©
CLIR: Presentation of one's own number to the to the called party
Activate CLIR **31#©
Activate CLIR for the actual call *31#number©
Deactivate CLIR ##31#©
Deactivate CLIR for the actual call #31#number©
Check status of CLIR *#31#©

COLP: Current reached number presentation (If called number was diverted from another number
Activate COLP *76#©
Deactivate COLP #76#©
Check status of COLP *#76#©

COLR: Calling Party's called number presentation (if the call is diverted to his cellphone) Activate COLR *77#©
Deactivate COLR #77#©
Check status of COLR *#77#©

GSM Network Service Codes
11 Speech
13 fax
25 data
In the future one will be able to control each individual call by use of the following service codes. To do this the user has to insert the service code in front of the last # in the MMI command above.
For example the sequence *21*number*16# would divert all SMS calls (and only these) to the given number.

Cell phone Services
10 All types of cellphone services
11 Speech service
12 Data service
13 Fax
14 Datex-J
15 Teletex
16 Short message service (SMS)
18 All data services without SMS
19 All cellphone services without SMS

Carrier Services
20 All services
21 All asynchronous services
22 All synchronous services
23 3.1 kHz services
24 Synchronous point-to-point connections including PAD's (all synchronous data services)
25 Asynchronous point-to-point connections including PAD's (all asynchronous data services)
26 Data packet sending including PAD's (all synchronous data packet services)
27 Services with PAD-share
29 Digital connections with 12kbps