Although on the face of it Mexico has reasonably efficient postal and telephone systems, phoning home can be a hazardous business, while packages have a tendency to go astray in both directions. One thing to watch is the outrageous cost of international phone calls, faxes and telegrams - call collect or use a calling card wherever possible

Mexican postal services ( correos ) are reasonably efficient. Airmail to the capital should arrive within a few days, but it may take a couple of weeks to get anywhere at all remote. Post offices (generally Mon-Fri 9am-6pm, Sat 9am-noon) usually offer a poste restante/general delivery service: letters should be addressed to Lista de Correos at the Correo Central (main post office) of any town; all mail that arrives for the Lista is put on a list updated daily and displayed in the post office, but held for two weeks only. You may get around that by sending it to "Poste Restante" instead of "Lista de Correos" and having letter-writers put "Favor de retener hasta la llegada" (please hold until arrival) on the envelope; letters addressed thus will not appear on the Lista. Letters are often filed incorrectly, so you should have staff check under all your initials, preferably use only two names on the envelope (in Hispanic countries, the second of people's three names, or the third if they've four names, is the paternal surname and the most important, so if three names are used, your mail will probably be filed under the middle one) and capitalize and underline your surname. To collect, you need your passport or some other official ID with a photograph. There is no fee.

American Express also operates an efficient mail collection service, and has a number of offices all over Mexico - most useful in Mexico City, where the address for the most central branch is: c/o American Express, Reforma 234, Col. Juarez, México D.F. They keep letters for a month and also hold faxes. If you don't carry their card or cheques, you have to pay a fee to collect your mail, although they don't always ask.

Sending letters and cards is also easy enough, if slow. Anything sent abroad by air should have an airmail (por avión) stamp on it or it is liable to go surface. Letters should take around a week to North America, two to Europe or Australasia, but can take much longer (postcards in particular are likely to be slow). Anything at all important should be taken to the post office and preferably registered rather than dropped in a mail box, although the new special airmail boxes in resorts and big cities are supposed to be more reliable than ordinary ones.

Sending packages out of the country is drowned in bureaucracy. Regulations about the thickness of brown paper wrapping and the amount of string used vary from state to state, but most importantly, any package must be checked by customs and have its paperwork stamped by at least three other departments, which may take a while. Take your package (unsealed) to any post office and they'll set you on your way. Many stores will send your purchases home for you, which is a great deal easier. Within the country, you can send a package by bus if there is someone to collect it at the other end.

Telegram offices (Telegrafos) are frequently in the same building as the post office. The service is super-efficient, but international ones are very expensive, even if you use the cheaper overnight service. In most cases, you can get across a short message for less by phone or fax.

Local phone calls in Mexico are cheap, and some hotels will let you call locally for free. Coin-operated public phones, rapidly disappearing, also charge very little for local calls. Internal long-distance calls are best made with a phonecard. These are available from telephone offices and stores near phones that use them (especially in bus and train stations, airports and major resorts). Many newer public phones say they accept credit cards; in practice, however, they often don't.

Slightly more expensive are casetas de teléfono , phone offices where someone will make the connection for you. There are lots of them, as many Mexicans don't have phones of their own: they can be simply shops or bars with public phones, indicated by a phone sign outside, in which case you may only be allowed to make local calls, but many are specialist phone and fax places displaying a blue-and-white Larga Distancia (long-distance) sign. You're connected by an operator who presents you with a bill afterwards - once connected, the cost can usually be seen clicking up on a meter. There are scores of competing companies, and the new ones, like Computel, tend to be better; many take credit cards. Prices vary, so if you're making lots of calls it may be worth checking a few out. There are casetas at just about every bus station and airport.

Wherever you make them from, international calls are fabulously expensive - using a phonecard is probably the cheapest option, though even the highest denomination ones won't last long; next best rates are from a caseta (though costs vary more than you'd expect, so shop around); calling from a hotel is very extravagant indeed. Charges vary a great deal, but typical caseta prices are US$3 a minute to call the US, £4 a minute to the UK. If you plan to make international calls, by far the best plan is to arm yourself in advance with a charge card or calling card that can be used in Mexico; you'll be connected to an English-speaking operator and will be billed at home at a rate that is predictable (if still high). You should be able to get through to the toll-free numbers from any working public phone.

Next best is to call collect ( por cobrar ). In theory you should be able to make an international collect call from any public phone, by dialling the international operator (tel 09) or getting in touch with the person-to-person direct dial numbers we've listed, though it can be hard to get through. At a caseta there may be a charge for making the connection, even if you don't get through, and a hotel is liable to make an even bigger charge.

Faxes can be sent from (and received at) many long-distance telephone casetas: again the cost is likely to be astronomical

 The Internet is booming in Mexico - most urban school children are computer-literate and public access facilities are springing up all over the place. Internet cafés are easy to find in all the larger cities and the level of service is usually excellent, although servers tend to crash with greater frequency than they do at home. In smaller towns and villages, such facilities are still rare. Prices start at around US$1 per hour and can be inflated to five times that amount in touristy areas. If you are in such an area, look for cheaper Internet cafés around the town centre that are frequented by the locals and avoid those in the luxury hotel zones. Internet facilities in large cities are usually open from early morning until late at night, but in smaller towns they have shorter opening hours and close altogether at weekends