The Stratus Web Portal allows users to have email notifications sent to the user when a voicemail arrives in their inbox. A guide to this set up in detail can be found here.
An additional option is have a text message sent instead of, or in addition to, an email.
Several cellular carriers have email syntax for sending SMS text messages via an email address.
A list of some of common carriers and their email to sms syntax is below.
- T-Mobile – number@tmomail.net
- Virgin Mobile – number@vmobl.com
- AT&T – number@txt.att.net
- Sprint – number@messaging.sprintpcs.com
- Verizon – number@vtext.com
- Tracfone – number@mmst5.tracfone.com
- Ting – number@message.ting.com
- Boost Mobile – number@myboostmobile.com
- U.S. Cellular – number@email.uscc.net
- Metro PCS – number@mymetropcs.com
These can be added to a users profile, within the Stratus Web Portal, in order to have an email sent to your sms number. 
These text messages will contain the exact same information as a regular email. Because of this, the contests of the message may have an 'odd' appearance. However, the goal of text notifcations is to inform the user that they have a new voicemail via text message, and this accomplishes the task. 
Notes:
- If you select the unfied messaging option that has 'move to trash', it is important to keep in mind that the text will NOT contain an attached audio file. You are able to add additional email addresses using the green plus button, so that you can add a valid email address where the audio file can be accessed.
- If you receive a high number of voicemail messages, you could find your domain blocked within a very short period of time. Mobile carriers have every incentive to limit this type of communication and they can do so at their own discretion. If they think you are spamming or getting too much use out of this texting loophole, they will not hesitate to throttle your traffic or block your messages entirely
- Message and data rates apply. Text message and data fees that you as the consumer pay apply to the automated text messages that you are opting in to receive. Contact your sms provider to review any limitations on your sms rates.